In the dark days following the declaration of war with Germany, plans devised in the 1930s to protect the country from the worst excesses of the expected air war were put into action. Children were evacuated from London and other major cities, gas masks were distributed and an air raid protection system was established.

But it wasn’t only children who were evacuated at the outbreak of war: paintings, sculpture, manuscripts, books, records and countless other priceless treasures were disbursed to stately homes, castles, quarries and public buildings around the country in a desperate bid to protect the nation’s cultural heritage.

At the outbreak of the Second World War, the British Government and people feared two things more than anything else: a successful German invasion or the blanket bombing and obliteration of Britain’s cities from the sky.

Of these, the second had been the ominous subject for bleak prophecies and warning tracts since the development of the airplane. In November 1932, the Prime Minister Stanley Baldwin summed up the position in a dour, if realistic, assessment:

“it is well also for the man in the street to realise that there is no power on earth that can protect him from being bombed. Whatever people may tell him, the bomber will always get through.”

It was a widely held belief, echoing the work of the Italian General Douhet and the author of The Command of the Air. Douhet had predicted that the destruction of an enemy’s military and industrial capabilities from the air could see wars won without the need for land forces. The nightmarish visions of death and destruction delivered impersonally from beyond the clouds had been worked into novels, articles and films and were common currency amongst a fearful people.

It was no surprise, therefore, that the Government sought to protect some of its most precious things. Children were top of this lift, with the evacuation programme well underway by the declaration of war in September 1939.

But what of the priceless treasures crammed in the nation’s museums, galleries, collections, libraries and records? A disproportionate number were housed in the great national institutions in London and where intensely vulnerable to bombs and fire. A nightmarish vision saw the Doomsday Book and copies of the Magna Carta incinerated in a firestorm, the Elgin Marbles crushed beneath the rubble of a direct hit or Constable’s The Hay Wain obliterated in a shower of flying glass and mortar.

It was eventually decided that these too would have to be evacuated. The artefacts were to be carefully packaged, boxed, crated and removed to safe keeping far from the capital and other cities. But with nowhere entirely safe from aerial attack, how did the Government intend to protect the nation’s heritage and cultural riches? Each institution had its own plans for how best to preserve and protect the cultural riches with which they were entrusted.

Although faded parchments and cracked record books might struggle to compete with paintings and porcelain for artistic merit, they ranked higher in priority than the finest artistic treasures in deciding what was to be protected. The Public Records Office has records dating back to 974 and an unbroken collection of royal decrees and proclamations covering every monarch since William the Conqueror.

Soon after war was declared on Germany, the archivists set to work bundling and packing the most precious of these records and dispatching them in convoys to Belvoir Castle in Leicestershire and a disused prison at Shepton Mallet. At Belvoir Castle, tonnes of documents were piled in the stately home’s ballroom, guards’ room and around the maze of corridors that connected the service quarters.

Books would accompany paper records in being evacuated to safety outside London, with some of the rarest manuscripts and books being sent for safekeeping to the national libraries of Wales and Scotland in Aberystwyth and Edinburgh respectively. The basement of the Bodleian Library in Oxford and stately homes such as Daglingworth Rectory, Lypiatt Park and Tring were also used.

Perhaps the greatest concentration of artistic treasures was buried in a heart of a Welsh mountain. Manod Quarry in Blaenau Ffestiniog was far from any likely bombing targets and provided a solid fortress hewn from rock. The storage rooms had been specially adapted with heating, drainage and ventilation in preparation for their precious guests. The rooms even had hydrometers installed so that the humidity and dampness of the rooms could be monitored.

This unlikely corner of Snowdonia is the most likely location for the temporary wartime home to the actual Crown Jewels (although the actual location for the safekeeping of the regalia is still officially a state secret). What is known for certain is that it guarded the metaphorical crown jewels of the UK’s art collection.

But Manod Quarry was not the first place the paintings were taken to. Rembrandts, Van Dykes, Leonardo da Vincis and Gainsboroughs had been carefully taken down from their hangings in the days leading up to the outbreak of war. The National Gallery was closed to the public on 23 August 1939 and quickly stripped of its priceless collection.

Similar operations took place at the National Portrait Gallery, the Royal Collections and the Tate, with storage found in Mentmore House in Buckinghamshire (for the NPG) and Eastington Hall in Worcestershire, Hellens at Much Marcle in Hereford and Muncaster House in the Lake District (for the Tate). The storage provided by the aristocracy was not always a selfless act in the national interest, as recorded in a letter received by the Assistant Keeper of the Tate from owner of Muncaster House:

“I welcome the prospect of housing here pictures from the Tate Gallery – in the event of war… their presence here might help preserve us from, or reduce the number of, the threatened hordes of small children.”

The paintings were packaged up and then travelled to Wales in vehicles disguised as delivery vehicles for a chocolate company. The collections had been broken up and distributed amongst a variety of places, including the University of North Wales at Bangor, The National Library of Wales in Aberystwyth, Caernarvon Castle, Trawsgoed and Penrhyn Castle.

Some experts recommended the collection be sent to Canada for safekeeping. Churchill took the determined decision not to ship the paintings overseas for fear of U-Boat attack and a cultural calamity on the oceans. He had told Kenneth Clarke, the director of the National Galley, to: “Hide them in caves and cellars, but not one picture shall leave this island.” With that command, the collections were sent to the caves and caverns of the Welsh quarry.

Some precious things were, however, deemed suitable to be sent to Canada – between the declaration of war and August 1940, 2,154 tons of gold were taken from the Bank of England, shipped over the Atlantic and lodged in the vaults of the Bank of Canada in Ottawa.

London’s vast cultural collections meant there was still substantial work for the preservation teams. The Victoria and Albert Museum faced the problem of what to do with some truly gigantic works of art. Quarries and stately homes once again proved to be a winning combination, and the bulk of the South Kensington collections were sent to Westwood Quarry in Wiltshire and to Montacute House in Somerset.

Some of the pieces found safety closer to home in the tunnel near Aldwych tube station. The Holborn to Aldwych branch of the Piccadilly Line was closed allowing it to become a temporary repository of the museum’s collections. The largest and most immobile items, such as the Raphael cartoons, were protected as best as possible in the main museum, sand-bagged and bricked in for the duration of the war.

This leaves what was perhaps the largest and most complex cultural evacuation of the war: the vast, iconic and priceless ethnographic and artistic treasures of the British Museum. They would find homes side by side with the collections of the V&A – in Westwood Quarry and the Aldwych tunnels.

The Elgin Marbles became one of the most famous pieces to stay behind, stored in the deep level tunnels of the Piccadilly Line. It was a fortunate move, as their usual home, in the Museum’s Duveen Gallery, was to be badly damaged in enemy bombing raids. Were they safe in the tunnels? Perhaps not – post-war calculations confirmed that a direct hit would have destroyed the Aldwych Station and its tunnels.

Across the Capital, collections were being stripped for safekeeping – pieces from the Imperial War Museum, the Wallace Collection, the Royal Armouries and many other galleries and museums in both London and the UK’s other major cities were being despatched to a network of remote stately homes, castles and quarries.

The operation was hugely successful, with one historian of the evacuation stating that only one major painting from a London collection was burnt in the blitz. Ironically titled The Destruction of the Children of Niobe, this piece, by Richard Wilson and owned by the Tate, was destroyed when a West End art restoration workshop was bombed.