His voice was the soundtrack to Brexit. The drawn-out cries of “Orderrrrr” during fractious but historic late-night votes, the dramatic pauses before announcements that would shape the course of Britain’s EU withdrawal, the long-winded but momentous rulings that dashed the hopes of successive prime ministers.

John Bercow will step down as House of Commons speaker on Thursday having outlasted three prime ministers and presided over 10 of the most seismic years in British political history.

While some MPs are already lamenting his retirement, others are delighted to see the back of one of the most divisive speakers in modern history.

In fact, to say that Bercow was controversial would be to understate the animosity he inspired in some.

Despite having served as Tory MP for Buckingham for 12 years before being elected as speaker in 2009, his habit of siding with parliament against the government meant he quickly became more popular with other parties than with his own.

He is despised by many Conservatives for his long-winded and often self-aggrandising monologues, his abrupt rebuttals and at times petty way of dealing with dissenters and, most of all, for his eyebrow-raising rulings.

To his critics, he is an ardent Remainer who has indefensibly abused his position and repeatedly ripped up the rulebook in a bid to frustrate Brexit.

To his allies, though, he is a reformer who has repeatedly defended the rights of the House of Commons in the ongoing power struggle with the executive.

What both sides agree on is that Bercow’s rulings in recent years have had an immeasurable impact on the course of Britain’s political future and the workings of parliament for years to come.

A series of major decisions, all of them contentious, guarantee that he will be a major figure in the history books when the Brexit saga is written up for posterity.

First, he stopped Theresa May holding a third “meaningful vote” on her Brexit deal – a decision that forced her to affectively abandon the agreement she had spent months negotiating, and rapidly hastened her demise.

Bercow made a similar ruling against Boris Johnson earlier this month, forcing the prime minister to change tack and first try to introduce legislation turning his Brexit deal into law, and then seek a general election.

In between, he took the highly unusual step on several occasions of allowing backbenchers to seize control of the Commons timetable to pass laws blocking a no-deal Brexit – rulings so monumental that, without them, it is possible the UK would have crashed out of the EU by now.

Best pictures from Final Say Brexit march Show all 76 1 /76 Best pictures from Final Say Brexit march Best pictures from Final Say Brexit march Crowds march through central London Getty Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march Protesters gather in Parliament Square Led By Donkeys Best pictures from Final Say Brexit march Mayor of London Sadiq Khan joins protesters PA Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march Anti-Brexit protesters fill Parliament Square in London PA Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march A demonstrator marches EPA Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march Protesters push a float depicting Dominic Cummings using Boris Johnson as a puppet during the Final Say Brexit march in London PA Best pictures from Final Say Brexit march EU supporters react after the result of the vote on the deal delay was announced at the House of Commons REUTERS Best pictures from Final Say Brexit march A demonstrator carries his dog draped in EU flag AP Best pictures from Final Say Brexit march Thousands of people taking part in a People's Vote march AFP/Getty Best pictures from Final Say Brexit march Protesters use their flags to shelter from the rain Getty Images Best pictures from Final Say Brexit march Protesters march towards Parliament Square Getty Images Best pictures from Final Say Brexit march Anti-Brexit demonstrators carry placards and EU flags AP Best pictures from Final Say Brexit march Sir Oliver Letwin MP in Parliament Square, London, during an an anti-Brexit, Let Us Be Heard rally, after it was announced that the Letwin amendment, which seeks to avoid a no-deal Brexit on October 31, has been accepted PA Best pictures from Final Say Brexit march Thousands of people taking part in a People's Vote march UK BROADCASTERS POOL/AFP via Get Best pictures from Final Say Brexit march A protester with "Bollocks to Brexit" stickers on his head Getty Images Best pictures from Final Say Brexit march Demonstrators march EPA Best pictures from Final Say Brexit march Britain's main opposition Labour Party shadow Secretary of State for Exiting the EU Keir Starmer, shadow Home Secretary Dianne Abbott, shadow Chancellor of the Exchequer John McDonnell, shadow Foreign Secretary Emily Thornberry speaks on stage in Parliament Square AFP via Getty Images Best pictures from Final Say Brexit march Anti-Brexit supporters cheer outside 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London PA Best pictures from Final Say Brexit march Whippets are dressed in EU flag clothing during the Final Say Brexit march in London AP Best pictures from Final Say Brexit march Protesters march towards parliament in the Final Say Brexit march in London on 19 October 2019 PA Best pictures from Final Say Brexit march An anti-Brexit demonstrator takes part in the Final Say Brexit march in London AFP/Getty Best pictures from Final Say Brexit march EU supporters call on the government to give Britons a vote on the final Brexit deal Reuters Best pictures from Final Say Brexit march Anti-Brexit protesters Angela Christofilou/The Independent Best pictures from Final Say Brexit march An anti-Brexit protester Angela Christofilou/The Independent Best pictures from Final Say Brexit march Anti-Brexit protesters demonstrate in London during the Final Say Brexit march on 19 October AP Best pictures from Final Say Brexit march Protesters push a float depicting Dominic Cummings using Boris Johnson 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Each time, his decision provoked uproar from Conservative MPs. Each time, Bercow brazenly dismissed it.

It’s fair to say that self-confidence is not an area where Bercow is lacking, but he also saw himself as a reformer, so the objections of traditional Tories mattered little to him.

He announced as much in justifying one of his most controversial decisions: allowing backbenchers to amend a business motion (a Commons timetable) in January 2019 to force ministers to publish their Brexit strategy much earlier than they had wanted to.

Amid a furious backlash from Eurosceptics, the speaker told the Commons: “If we were guided only by precedent, nothing in our procedures would ever change. Things do change.”

The Commons Speaker: Eight candidates to replace John Bercow

Bercow has been credited with helping to modernise parliament, including relaxing House of Commons dress codes and allowing pregnant and unwell MPs to vote by proxy for the first time. He also helped oversee the introduction of a new grievance procedure for allegations of harassment and bullying.

This carried with it a certain irony, given that the speaker himself has been dogged by a number of allegations of bullying – all of them denied – in recent years.

Several Commons clerks have come forward to allege that he verbally harassed them on a number of occasions, in some cases so severely that one employee was reportedly left with post-traumatic stress disorder.

He was also criticised after appearing to refer to Andrea Leadsom, then the leader of the Commons, with whom he had a fractious relationship, as a “stupid woman”.

For all his insistence that complaints be properly investigated, there was no formal inquiry into Bercow’s conduct, after the Commons standards committee blocked a probe.

He will leave parliament without having been forced to answer questions about his conduct towards his juniors.

'The culture was toxic' John Bercow addresses house after angry exchanges about Brexit and the PM's language

Many people outside Westminster will know none of this. In the UK and beyond, John Bercow will be best remembered not for his constitutional rulings but for his bizarre style of chairing proceedings.

His manner of speaking, reportedly based on his impressions of Jane Austen characters, sparked news stories around the world and made him an unlikely celebrity in various nations.

His particular favourites included turning Tory MP Peter Bone’s surname into a five-second foghorn and calling Labour MP Thangam Debbonaire’s name​ to the tune of Bon Jovi’s “Livin’ on a Prayer”.

His put-downs also became legendary in Westminster, with barked orders for MPs to stop "chuntering from a sedentary position" and suggestions that they instead "take up yoga" among his favoured barbs.

None of this will be remembered for long, of course, and Bercow’s enduring legacy is on Brexit. Depending on what happens in the forthcoming election, he may be viewed in time as the man who empowered parliament to avert a catastrophic no-deal exit from the EU.