In the first of a three-part series, RTÉ Europe Editor Tony Connelly examines Britain's complicated history with Europe.

"The British Empire … was built by power, and sustained by power," the Daily Mail declared on 16 June 1961. But, the next lines are shocking in their frankness: "When that power was removed the edifice began to crumble."

The Mail continued its sobering analysis. Since World War II Britain’s empire had collapsed. It was dwarfed by America and Russia. It had been humiliated in the Suez Crisis. The only way for Britain to retrieve its greatness was to join "Europe".

"Britain is essentially a European country. She has derived her strength from Europe, and the Empire was built up through her assertion of power on the Continent."

How surreal to read those words today given the Mail’s chest-thumping nationalism.

As Britain brutally reverses the sentiment expressed all those years ago, the psycho-drama of her post-war attitude to Europe, as it played out over seven decades, seems bafflingly contrary to the current zeitgeist, yet at the same time all too familiar.

From 1945 until the late 1980s, it was the Conservatives who were the champions of Britain in Europe, not Labour. The great Tory statesmen who played their part in the drama – Winston Churchill, Anthony Eden, Harold Macmillan, Ted Heath – more or less saw Europe as Britain’s only hope of retaining influence in a rapidly changing world.

Anti-Europeans convinced themselves that Britain was the unbound, free-trading Titan, leading the world to a civilised future. She enjoyed a sacred bond with the US, and she presided over the Commonwealth.

A number of books have explored Britain’s tortured relationship with Europe. The standout has been This Blessed Plot: Britain and Europe from Churchill to Blair, by the late Guardian political journalist Hugo Young.

But a new book explores in greater details the internal contradiction in Britain’s political class.

Continental Drift: Britain and Europe from the End of Empire to the Rise of Euroscepticism, is an exhaustive study by Benjamin Grob-Fitzgibbon, a British-born historian and current American diplomat, of how the UK agonised its way into the EEC in 1973, and then tumbled out of the EU 43 years later.

Grob-Fitzgibbon, who has written works on Ireland during World War II and the Irish War of Independence, depicts a political class shocked into re-assessing its role at the end of the war, then finding itself frantically trying to weigh up its best course of action as, one by one, the certitudes of the nation’s storied majesty fell away: its empire was faltering, the six founding members of the European Community were beginning to forge a future that looked economically stronger, and the bipolar struggle of the Cold War was rapidly dwarfing Britain’s importance on the world stage.

One well worn trope, oft repeated since the Brexit referendum, is that whereas the rest of Europe has an emotional, romantic attachment to the EU, Britain’s has always been hard-headed and transactional.

Grob-Fitzgibbon has trawled a thicket of diaries, correspondence, primary and secondary sources in order to arrive at a perhaps more pungent conclusion: Britain’s attitude to Europe has been neither emotional, nor pragmatic, but neurotic.

Rather like an insecure lothario, Britain between 1945 and 1970, when its third and successful bid to join "Europe" got under way, was, having been spurned by the Prom Queen, fretfully casting about for a plain Jane terrified that it would be left on the shelf.

An imperial superpower at the turn of the 20th Century, Britain was victorious at the end of World War II, with a strong sense of its own defiance and heroism.

In This Blessed Plot Hugo Young portrays the unquestioning sense of Britain’s transcendent greatness.

This illusion permeated official and literary Britain; even a writer like George Orwell, who was viscerally critical of Britain’s class-ridden society, remained convinced that his country would claim a great role in the world.

"Victory," wrote Young, "confirmed a good many things that the country wanted to know about itself. The expression of it – of the assurance it supplied to an idea of nation that long preceded it – reached beyond economists, generals and politicians.

"If you look at what British writers were saying about England before and after the war, you read for the most part a seamless paean to the virtues of the nation’s strength and identity."

And yet… Britain’s economy was in ruins and it was hopelessly in debt. It was only those at civil service level who recognised this and who dared speak a word of warning.

One was Sir Henry Tizard, chief scientific adviser at the Ministry of Defence. In a memo he wrote: "We are not a Great Power and never will be again. We are a great nation, but if we continue to behave like a Great Power we shall soon cease to be a great nation."

Both the physical destruction of Britain’s cities, and the benighted European landscape had, in fact, weighed heavily on Winston Churchill.

To the East was emerging a baleful Soviet Union, and to the West the capitalist United States. Nevertheless, Churchill still saw Britain as the natural leader of Western Europe and had done so as far back as 1938, when he posited the notion of a "United States of Europe".

Churchill had intellectually conflated the traditions of empire and Christian heritage as giving Europe a world "civilising" role.

Remove the ancient irrational hatreds, and the "tangled growth and network of tariff barriers designed to restrict trade and production", he wrote, and a new Europe could be born.

Britain’s place in it was ambiguous, however.

Churchill saw Britons as of Europe, and apart from it. The country had an extra-European responsibility as the head of a huge empire.

The two weren’t mutually exclusive; indeed Britain’s colonies, and those of France, could provide the manpower, resources and genius to help Europe on its way, and to rival the US and USSR in the balance of power.

Britain had to lead both the Empire and Europe. Furthermore, with America threatening to taper off economic support to Europe, a united Europe led by Britain was the only way to counter the rising Soviet threat.

This was the message that Churchill as Tory leader carried into the general election in 1945, an election he promptly lost.

The Labour government, which won by a landslide, faced a world in flux.

Russian troops were brutally underpinning the Communist ascent to power in eastern Europe, no one knew what to do with a destroyed Germany, and in the Middle East the violent birth pangs of the state of Israel were threatening a key front of the British Empire.

This was a period of grand, panicky ideas. The replacement of one totalitarian system (fascism) with another (Soviet communism), the existential threat of atomic warfare, the destructive legacy of the war, all convinced desperate thinkers to conceive of organising humankind along a new concept of world cooperation.

For Churchill, now enjoying the dubious luxury of life in opposition, it was a period of florid policy explorations and speeches. In an address to the Belgian senate he talked of Britain’s "special associations". Europe, America and Russia had an "interlocking" character.

In Fulton, Missouri, he made his famous Iron Curtain speech. But he also spoke of Britain, America and the Commonwealth pooling their resources to provide over-arching security for the world.

In further speeches, most famously in Zurich in 1946, Churchill repeatedly fantasised about a United States of Europe, of a Europe rising again in "glory".

Warming to his theme he urged reconciliation between France and Germany, the equal treatment of small and large nations, spoke of a common defence and currency, and the creation of a Council of Europe.

For the first time Churchill located Britain at the centre of such arrangements, while at the same time being head of a world Empire.

"In Zurich, and in Collier’s Weekly," writes Grob-Fitzgibbon, "Churchill firmly attached his flag to the mast of European unity."

The new Labour foreign secretary Ernest Bevin was galled by Churchill’s visions.

He was much more convinced of the pre-eminence of the British Empire than any new European arrangements, although he believed, like Churchill, that as colonial powers, France and Britain should act in concert.

In the following years British politicians, civil servants, diplomats and the press all warmed to European unity with Britain at its heart.

The Empire or Commonwealth would somehow be on board as a counterweight to American imperialism and Russian dominance. In a letter to the Archbishop of Canterbury, Churchill wrote: "Britain has special obligations and spiritual ties which link her with the other nations of the British Commonwealth. Nevertheless, Britain is an integral part of Europe and must be prepared to make her full contribution to European unity."

Such visions infused the embryonic British United Europe Committee, later the United Europe Movement. The public, desperate for a guiding light in the post-war darkness, was enthusiastic.

It received a massive boost when the American Secretary of State George Marshall announced his eponymous aid package for Europe on 5 June 1947.

With Marshall urging Europeans to come together to make the Marshall Plan work, Churchill seized the opportunity.

He encouraged similar European movements elsewhere, and they were springing up in Belgium, France, the Netherlands.

A Congress of Europe was held in The Hague in May 1948 attended by leading British parliamentarians, novelists, poets, philosophers, industrialists and religious leaders.

Europe’s hour appeared to have arrived. Out of the process led by Churchill was born the Council of Europe, whose federalist notions, such as an elected European Parliament and a European Court, were later crystallised into the European Union. (The Council of Europe remains a separate organisation to this day).

But the euphoria of The Hague was shortlived.

Churchill’s greatest opposition was to be found at home, in the Labour government.

Ernest Bevin, the Foreign Secretary, was hostile to a United States of Europe, as it precluded the Soviet Union and could even lead to war with Russia.

Labour was deeply suspicious of anything which eroded sovereignty, and wanted Germany out of any new European framework.

But Bevin had other problems to worry about. In February 1947 Britain was forced to hand Palestine over to the United Nations, and to announce that British rule would end in India just over a year later. The Empire was beginning to crumble.

The Soviet Union was also becoming more belligerent, flatly opposing the US Marshall Plan and tightening its grip on central and eastern Europe.

Bevin was not opposed to European integration as such, but he wanted a more modest approach. His response was a Western Union of countries which would become – with the help and resources of the colonies – a bloc to stand between Russia and America.

While Britain waxed and waned, France grabbed the initiative.

The Schuman Plan, named after the French foreign minister, would create a supranational authority in Western Europe to control all coal and steel production. Bevin was shocked: the French had kept London in the dark, and for the first time sought explicitly to draw West Germany into its embrace.

The British general election of 1950 deepened the disconnect.

Whereas every election campaign that year across Europe focussed on European integration, in Britain the parties were fixated on the crisis facing Empire.

A young Conservative candidate called Margaret Thatcher ran for the first time.

That disconnect would be decisive. Within six weeks the French cabinet formally endorsed the Schuman Plan with German, and, crucially, American support (Washington was simply desperate for some kind of European unity to get off the ground).

The new, much reduced Labour government had been kept entirely out of the loop and at a stroke the notion of an Anglo-French engine of leadership had been replaced by a Franco-German one.

The Tories pounced on Labour’s indecision, hailing, not for the first time, the idea of European unity and praising the Schuman Plan.

The future prime minister Macmillan described it as "an act of high courage and imaginative statesmanship".

The British press was largely in favour: the Daily Mail attacked the government for not supporting it, but the Daily Express called it “a deliberate and concerted attempt to force Britain into a United Europe”.

France held out the prospect of Britain joining what would become the European Coal and Steel Community, but the notion of pooling sovereignty, even in such a narrow field, was a bridge too far.

With Britain a major coal producer, sharing such a resource wouldn’t fly either. In the famous words of the deputy prime minister Herbert Morrison, "the Durham miners would never wear it".

France, West Germany, the Netherlands, Belgium, Italy and Luxembourg forged ahead "to pursue a common action for peace and European solidarity".

Britain stayed out.

In October 1951, the Conservatives returned to power, and Churchill was once again prime minister.

It was a period of global instability with the Korean War and deepening revolt across the British Empire.

Churchill had still been, during the election campaign, a firm believer in European Unity, even canvassing the idea of a European Army.

But once in office his tone changed. Civil service briefing papers were peppered with terms such as "active part" and "leading role", but there was always the qualification that Britain could not accept any joint authority in Europe.

In a cabinet memorandum, Churchill acknowledged he had given the spark to European unity with his 1946 Zurich speech but he tutted that federalism was gathering strength, and that was never his intention.

Britain’s need to straddle multiple spheres of influence was also proving difficult.

Churchill had, during the campaign, wanted the Commonwealth to be somehow bound into any new European structures, but the notion was given a chilly response by both European and Commonwealth leaders.

Churchill’s foreign secretary Anthony Eden was even more hostile to any notion of Britain merging in a federative process.

He caused consternation among his own civil servants and the Council of Europe – also alarming the future president and current Supreme Commander of Allied Forces in Europe Dwight D Eisenhower – when he appeared to slam the door on Britain’s participation in a European Defence Community, the entity Churchill himself had actually proposed a year before.

Churchill appeared torn, but left Eden in charge of a policy which would contradict much of his post-war idealism on Europe.

Britain would fully support the integration of Europe, but would always stop short of anything that smacked of federalism. "There was, however" writes Grob-Fitzgibbon, "no question of a full embrace of Europe".

In sentiments which appear astoundingly similar to Theresa May's today, Churchill was claiming to support European integration as much as possible, but not fully embracing it because Britain would always prioritise the United States and the Commonwealth.

Britain’s slow detachment from the ideals and aims of European unity, which Churchill had done so much to foster, was becoming clear.

Eden repeated to the new US Secretary of State John Dulles that Britain would have a "leadership" role in Western Europe, but could never pool sovereignty precisely because of its leadership of the Commonwealth and its special relationship with America.

Compare this to May's Davos speech in which she claimed that leaving the EU would allow Britain to become even more “global”.

But in the early 1950s Washington was growing impatient with French and British posturing, especially over the creation of a European Defence Community (EDC).

Squabbles over Britain’s lack of involvement, and West Germany’s post-war rehabilitation, were holding up the kind of European integration the US believed was vital in resisting the Soviet threat.

The EDC had been regarded as an alternative to West Germany joining NATO, but the French were alarmed at any prospect of the German rearmament.

When the EDC collapsed (Britain was never going to be a member), Macmillan, then housing minister, proposed the establishment of the Western European Union (WEU) that would build upon the aims of the Treaty of Brussels, a mutual defence pact signed by Britain, France, Belgium, the Netherlands and Luxembourg in 1948.

With the WEU also promoting economic and social recovery in Western Europe, Italy and West Germany were effectively brought into the fold (West Germany would enter NATO through the back door of the WEU the following year).

France reluctantly ratified the WEU in March 1955. One week later Churchill, aged 80, resigned as prime minister.

As a vehicle that would reconcile Britain’s conflicting interests, America’s craving for European unity, and West Germany’s entry into NATO, the WEU as a high point in post-war integration was short lived.

Almost immediately the six founders of the European Coal and Steel Community felt that the WEU was not strong enough to facilitate deeper European integration.

The Six, as they became known, (France, West Germany, the Netherlands, Belgium, Italy and Luxembourg) met in Messina in Sicily in June 1955 to discuss, among other things, the idea of a European Common Market.

Britain was immediately sceptical: London had been invited, but Eden, who succeeded Churchill as prime minister, refused to attend, sending an observer instead.

Indeed, the Messina conference, which was the very embryo of the future expansive European integration, did not actually evoke much press enthusiasm either in London or across the Continent.

In any event, Britain was distracted by the cracks in empire. Insurgencies were breaking out in Cyprus, Malaya and Kenya.

Worse was to come. In November 1954, the Egyptian army officer General Gamal Abder Nasser overthrew the government and ushered in a wave of Pan-Arab nationalism that was a direct threat to British interests in the Middle East.

It all prompted some sobering analysis within the Tory government.

A memorandum prepared by the Treasury, Foreign Office and Ministry of Defence painted a bleak picture.

The US and the Soviet Union were taking their place as the two nuclear-armed world super powers.

West Germany was growing economically. The Commonwealth was becoming increasingly self-confident, with some members tilting away from empire and towards independence.

Britain’s inability to compete at the highest level or to influence events was becoming painfully obvious.

Alarmed at being caught between the twin stools of European integration and uncontrollable shifts in geo-politics, officials in Whitehall produced what became known as "Plan G".

It proposed a European free trade area between the Six and other members of the Organisation for European Economic Cooperation (OEEC, later to become the OECD), which had been set up to administer Marshall Aid.

Again, it is remarkable to note how London’s angst in 1955 is being relived today, with free trade agreements being the battleground.

Back then Plan G envisaged a trade relationship involving tariff-free access for British goods over time to what would become the Common Market, but which would allow Britain to maintain preferential trade deals with the Commonwealth countries.

Plan G insisted there would be no surrender of national sovereignty and involve no supranational authority.

"Under its terms," notes Grob-Fitzgibbon, some time before Boris Johnson famously asserted the idea, “Britain could have its cake and eat it, too, aligning itself with its European neighbours without in any way distracting from its Commonwealth relations.”

However, Plan G critically recognised the United Kingdom’s dilemma.

Implicit was the need for Britain to somehow embrace the nascent Common Market without throwing away its Commonwealth commitments.

Having cake and eating it was not a luxury. Harsh economic truth meant it was a desperate necessity.

Macmillan, now the Chancellor of the Exchequer and still a committed European, felt Plan G would be the first step in acclimatising the British public that “Europe” was where Britain’s destinies lay.

Others in the Tory government warned that it would fatally loosen Britain’s bonds with Empire and Commonwealth. Lord Home, the Commonwealth Secretary, felt it would "weaken … the United Kingdom as a world power".

Macmillan won the cabinet debate. Plan G was presented to the public in a news conference on 3 October 1956.

With a relatively benign response from the US, Europe and a number of Commonwealth countries, who said they had no objection to it, Plan G was adopted as government policy at the Tory Party conference two weeks later.

But problems were looming elsewhere.

Britain had occupied Egypt since 1882 rendering the country both a British protectorate and part of the Ottoman Empire.

Although Egypt had won independence in 1936, London still owned a majority of shares in the Suez Canal Company, and British troops protected it.

Seven months after seizing Nasser announced he was nationalising the Suez Canal in a direct challenge to British colonial interests.

The prime minister, Sir Anthony Eden, told Commonwealth leaders in Canada, New Zealand, Australia and South Africa that he would take action if necessary.

That action would have fatal consequences for Britain’s place in the world, and its standing, in particular, in the eyes of the Americans.

On 24 October 1956, Britain entered a secret agreement with Israel and France that Israel would invade Sinai, triggering an "intervention" by British and French forces to separate the warring Israeli and Egyptian sides.

The Anglo-French force would then "protect" the Suez Canal.

On 29 October Operation Muskateer went ahead as planned, but it quickly became a diplomatic and public relations disaster.

Commonwealth leaders quickly condemned the action, but worse was to come.

Saudi Arabia, then the United States, announced an oil embargo against Britain and NATO countries followed suit. Britain was forced into a humiliating climbdown, announcing first a ceasefire then a withdrawal of British troops.

The episode damaged Britain’s standing in all spheres: America, Europe and the Commonwealth. Her ambitions to lead in Europe and the Commonwealth lay in tatters.

"In the years after the Second World War," writes Grob-Fitzgibbon, "Britons – both Conservative and Labour – had acted as imperial Europeans, confident in their place in the world, and convinced that their empire gave them the right and the responsibility to re-organise Europe and lead it to greatness.

"In the aftermath of the Suez crisis, the government’s only certainty was that the place Britain held in the world was no longer what it once was."

"In January 1957, the government turned to Europe, not out of a presumptuous arrogance of a right to lead; it turned to Europe because it had nowhere else to go.”

The Europe that Britain was turning to was forging ahead on its own.

On 25 March, France, Belgium, Italy, Luxembourg, West Germany and the Netherlands signed the Treaty of Rome, establishing the European Economic Community (EEC).

The Common Market, as Britain referred to it, would foresee the dismantling of tariffs, creation of a customs union, a single market for goods, labour, services, and capital, common agriculture policies, a European social fund.

It also established the European Commission.

Almost immediately Macmillan, who had succeeded Eden as prime minister in 1957, realised that if Britain didn’t act quickly to establish a European Free Trade Area (EFTA), which had been at the heart of Plan G, then it would be sidelined by a Common Market dominated by an economically resurgent Germany.

But Britain’s EFTA idea ran into immediate problems.

The French were suspicious that London was out to frustrate the launch of the EEC, the Germans were anxious not to upset the French, while Commonwealth countries were loathe tosupport anything that would jeopardise the so-called Imperial Preferences governing food and agricultural exports to the UK.

Macmillan’s response was characteristic of the contortions Britain had had to – and would continue to – perform in order to maintain its sense of global heft.

The Commonwealth would give Britain the power to lead a united Europe, he argued, while an economically strengthened Europe would revitalise the Commonwealth, whose products would be somehow part of the free trade arrangement.

Britain launched an EFTA charm offensive. While it won the tacit or overt support of a range of European countries (Ireland said it would agree to an EFTA in principle, but would need to see the fine print), there was scepticism in New Zealand and Australia.

The French, meanwhile, were hardening their opposition to an EFTA that would run parallel to the EEC.

General Charles De Gaulle, who had come to power on 1 June, 1958 against the backdrop of violent unrest in French-controlled Algeria, was even more hostile than his predecessors, establishing an implacable froideur towards Britain’s European ambitions that would become so decisive in later years.

The resistance was infuriating Macmillan who privately threatened that Britain would force France out of NATO, leaving what he called "Little Europe" to fend for itself in the event of a Russian invasion.

A meeting with De Gaulle in Paris was fruitless; De Gaulle hinted at a softening of his opposition, but only if Britain agreed to include agricultural produce as well as industrial goods in any EFTA-EEC framework – a non-starter for London given its Commonwealth obligations.

At the end of his patience, Macmillan prepared to announce that Britain was pulling out of negotiations, but De Gaulle beat him to it, saying that France could not accept Britain’s vision for Europe. The Times warned of a European trade war.

Here, again, was the forerunner of the struggles which – who knows – may be played out once again between Britain and the rest of Europe.

Stung by the notion that Britain’s ambitions to lead European unity had amounted to nought, Macmillan agreed, in the hope that it would give him more negotiating clout with the Six, to a free trade agreement encompassing non-EEC countries Sweden, Denmark, Norway, Switzerland, Portugal and Austria.

Already, notes Grob-Fitzgibbon, London was worried that American firms would pull factories “out of Northern Ireland” in favour of locating in the Common Market.

In November 1959 EFTA was finally signed, with seven members compared with the Six of the EEC.

Already, however, Macmillan could see the way the continental tide was turning.

He felt Britain needed to be closer to the EEC despite having just launched a rival organisation.

The Conservatives had just won a stunning electoral victory the previous month (a young Margaret Thatcher was chosen as MP for Finchly), but his officials were warning that sooner or later Britain would have to join the nascent powerhouse of the Common Market.

But at the turn of the new decade Macmillan’s focus would be elsewhere. Throughout the 1950s the British Empire had been crumbling: India, Burma, Sri Lanka, Sudan, the Gold Coast (renamed Ghana) and Palestine had all gone, Britain had brutally put down insurgencies in Kenya and Cyprus.

Macmillan’s instincts, expressed in his iconic "Wind of Change" speech to the South African parliament in Cape Town, were to manage the dissolution of empire in a way that would nurture the Commonwealth.

But his stance only served to alienate the biggest white-ruled Commonwealth countries who felt Britain was letting them down.

The wind of change also ushered in the uncomfortable reality: with more and more countries shaking off their colonial ties, Britain’s future lay less with the Commonwealth and Empire, and more with the United States and Continental Europe.

The realisation was acknowledged by a younger breed of politicians and civil servants, who had fewer sentimental attachments to empire.

Even the Daily Mail, as per the opening of this article, felt that Europe was now the only vehicle for Britain to recover its "greatness".

A sense of "greatness" was, however, also alive and well on the other side of the Channel and would prove inimical to Britain’s new found interest in Europe.

General De Gaulle had always nurtured a vision of an "exalted and exceptional destiny" for La Patrie; with the Suez Crisis and the situation in Algeria the vision was somewhat shop-soiled, but it could still be realised if France were to lead a Europe of nation states (he was much cooler on European federalism than the French founding fathers).

Utlimately De Gaulle believed that by dint of its geography and history, Britain could never enter the EEC.

While Macmillan initially pursued the idea of a wider free trade arrangement between the Seven of EFTA and the Six of the EEC, as a bulwark against what he feared was the revival of a "Holy Roman Empire", he privately wondered if Britain should contemplate joining the European Coal and Steel Community (ECSC) and the European Atomic Energy Community (Euratom).

His officials went further. Correspondence from Sir Frank Lee, the head of Macmillan’s economic steering committee in 1960, posits Britain on the upward curve towards eventual membership around about the exact same location on the downward curve that May has placed Britain today.

"We must", he wrote, "on economic grounds maintain the broad objective of the United Kingdom form part of a single European market."

Britain should seek "near identification" with the Common Market short of total absorption within it.

Despite the notion of a formal entry into the Common Market edging its way into Cabinet discussions, Macmillan was still torn, feeling such a move would abandon the other six members of EFTA.

A reshuffle brought Edward Heath, an ardent European, to the fore as Lord Privy Seal and Foreign Minister with a special responsibility for European affairs. Other pro-Europeans were brought into the Cabinet; soon discussion of a membership bid was no longer taboo.

An unsettling global environment also helped focus British minds. The flight of millions of East Germans to the West via Berlin since the war eventually prompted the Communist German Democratic Republic to build a wall which would become the physical symbol of the Cold War.

With a more belligerent Moscow threatening to deepen Europe’s divide, Britain adopted a decisive shift in attitude.

Signals were sent to the new Kennedy Administration that Britain regarded EFTA as a stepping stone to deeper European unity, something Washington was anxious to promote.

The shift in attitude was not only based on geo-political insecurity.

London was looking with alarm at the growing economic strength of the six EEC members.

On 31 January 1961, the Daily Mail opined Britain had rejected the mantle of European leadership because “she continued to regard herself as an imperial and oceanic power. Now, the empire is almost gone and Britain is one among a number of equal, sovereign Commonwealth states. In the meantime Europe has forged ahead.”

Officials were already sounding out how Europe, America and the Commonwealth might react, whilst impressing upon their interlocutors the need for Britain to balance its economic interests in Europe with its responsibilities to the Commonwealth. With sufficient positivity coming from Europe and America, on 26 February, Edward Heath told a meeting of the Western European Union that the United Kingdom was prepared to join the Common Market.

In a private meeting in Washington President John F Kennedy told Macmillan he supported Britain’s entry and would do what he could to convince De Gaulle of its merits, but there was an immediate backlash from New Zealand and Australia who feared that EEC membership would cut out their preferential trade deals with the UK.

In Britain a full-blown debate on EEC membership got under way for the first time. The Cabinet consensus was that industry would be the big winner, while British agriculture would suffer, but the loss in sovereignty was a price worth paying. Concerns about the effect on the Commonwealth lingered.

The British press was divided. Beaverbrook papers (Evening Standard, Daily Express and Sunday Express) were uniformly hostile, while the Times, the Daily Telegraph, the Daily Mail and the Daily Mirror were positive.

The Conservative Party itself was showing signs of the division over Europe that would bedevil it to this day.

As much of the angst related to the supposed betrayal of the Commonwealth, government ministers fanned out across Britain’s global dominions to sell the idea and to reassure leaders that they would not accept membership terms detrimental to Commonwealth interests.

But the Conservative narrative on Europe had changed utterly: unless Britain joined the EEC, which was becoming "a really effective economic and political force" according to a Cabinet memo, its influence in Europe would decline, and its "special relationship" with the US, and with the Commonwealth, would suffer as a result.

On 10 August 1961, Britain submitted its application to join the EEC.

In an address to the nation Macmillan couched the move specifically in terms of the Commonwealth:

“[T]he Commonwealth depends, of course, on sentiment and memories of the past. But important as these are it must look to the future.”

Only by joining the Common Market, he declared, could Britain be a better member of the Commonwealth.

The die was cast. But the divisions in Britain, which are still a running sore, would soon become apparent.

The Tory Party conference overwhelmingly endorsed the application to join the Common Market, but influential voices across the political spectrum, and in the press, were lamenting the loss of empire, the betrayal of the Commonwealth and the surrender of national sovereignty.

There was also mixed signals from the Six EEC members.

The Dutch, Germans, Belgians and Italians were delighted, but De Gaulle, predictably, was cool.

In November 1961 Macmillan invited the French president to his Sussex home to deliver a passionate appeal to a fellow "man of destiny", extolling the energy, diversity and markets Britain would bring by virtue of its Commonwealth connections to the European project.

At the same time he threatened that, should its application be rejected, Britain would quit NATO, turn away from Europe and allow a scenario where Germany could return to its belligerent ways.

De Gaulle responded that he would welcome the UK with open arms, but he did not quite see how Canadians, New Zealanders or Australians were Europeans, nor did he see a role for India in Europe.

The meeting got nowhere. What was most exasperating for Macmillan was that De Gaulle was like-minded in so many ways: both men were against federalism and in favour of a union of nation states; both were wary of a revived Germany.

Macmillan could only conclude that De Gaulle was driven by a visceral hatred of the English and an intense vanity for France.

At a further meeting in Paris in June 1962 Macmillan tried a different tack. Britain was ready to embrace Europe politically; a younger generation, not raised on Kipling and empire believed in it as an ideal which would replace the lost colonies.

De Gaulle responded that Britain would alter the character of the EEC, that it was too close to America, that it would always choose the Commonwealth over Europe.

Making things worse for Macmillan was that the Kennedy administration appeared to be confirming De Gaulle’s fears, so determined was it to encourage Britain’s entry.

At home, former pro-European Tory grandees were starting to have second thoughts about the terms of Britain join the Common Market if it meant loosening Commonwealth ties.

A small, but determined group of "anti-Marketeers" within the Tory bank benches were causing trouble by putting down motions linking Britain’s application to Commonwealth guarantees. Sensing a need to take control Macmillan carried out a brutal purge of his cabinet with the “Night of the Long Knives”, sacking anyone who had spoken out against the application, and promoting staunch Europeans.

Across the lobby the opposition Labour Party was fiercely anti-Europe, describing it as a capitalist conspiracy that would rob the UK of control of its own industrial policy, and would fatally undermine the Commonwealth.

At the Labour Party conference that October, leader Hugh Gaitskell claimed that EEC entry would end Britain as an independent state, would end "1,000 years of history", and put an end to the Commonwealth.

Public opinion was also souring. A poll showed in September 1962 that among swing voters, the numbers moderately opposed to entry had risen from 9% to 12%, while those who disapproved strongly had risen from 19% to a worrying 30%.

Macmillan was worried. In the run up to the Tory Party conference he decided to face the challenge head on, publishing a pamphlet that EEC membership was "the most forward-looking policy decision in our peacetime history … We in Britain are Europeans. That has always been true, but it has now become a reality which we can no longer ignore."

"We have to consider the state of the world as it is today, and not in outdated terms of a vanished past.”

The EEC, he declared, was the signpost towards a vision of the ultimate unity of mankind and Britain had to play its part.

His conference speech proclaiming a double victory for Britain in Europe and Britain in the world was greeted with enthusiastic acclaim.

But out in the country the mood was changing. In five by-elections the Tories lost two seats to Labour, and had reduced majorities in the other three.

One seat was lost because a Tory candidate running on an “anti-market” ticket badly split the Conservative vote.

The negotiations themselves were going badly, with Edward Heath accusing the French of being "ruthless" and "terrifying" the other five members by their "intellectual superiority, spiritual arrogance, and shameless disregard for truth and honour".

To rub salt in the wounds, the former US secretary of state Dean Acheson delivered his famous rejoinder at the Military Academy in West Point, accusing Britain of impeding Atlantic progress. "Great Britain," he declared, "has lost an empire and not yet found a role".

The role it was trying to play, its special relationship with the US, its leadership of the Commonwealth, was one that was "played out".

To make matters worse, De Gaulle was still obstructing, saying – ironically, given Acheson’s lecture – that the UK would always choose America over Europe. On 14 January 1963, De Gaulle delivered the killer blow to Britain’s membership aspirations.

He described Britain as "insular and maritime, linked by her trade, her markets and her food supplies to diverse and often far-flung countries".

Two weeks later the negotiations collapsed. Macmillan was devastated, and the fact that the rest of Europe blamed De Gaulle for the course of events was little consolation.

"We have lost everything," he wrote, "except our courage and determination".