Sir Keir Starmer was named after a founder of the party he has now been elected to lead.
The human rights lawyer, who says he has spent his life fighting injustice, was raised in Southwark, south London, by toolmaker father Rodney and nurse mother Josephine.
Labour supporters, they named him after Keir Hardie, the party's first parliamentary leader.
But his decision to accept a knighthood in 2014 made it trickier for Sir Keir to shake off perceptions of privilege – and allegations he is too middle class to speak to Labour's heartlands.
He studied at Reigate Grammar School and read law at Leeds and then Oxford before embarking on a legal career which saw him rise to be head of the Crown Prosecution Service.
His CV includes co-founding the renowned Doughty Street Chambers and advising the Policing Board to ensure the Police Service of Northern Ireland complied with human rights laws.
He entered Parliament as the MP for Holborn and St Pancras in 2015, speaking about the importance of equal rights for all in his maiden speech.
Sir Keir, 57, was quickly elevated to the frontbench, serving as a shadow Home Office minister before being promoted to shadow Brexit secretary soon after the EU referendum in 2016.
Despite clear divisions within the upper echelons of the party over the UK's exit, he remained in post for three and a half tumultuous years, shadowing three different secretaries of state as the negotiations tore holes into the Tories.
Sir Keir was instrumental in getting Labour to back a second referendum and said, at the party's conference in 2018, that "nobody is ruling out" an option for Remain being included on the ballot paper.
He has since said that the issue is settled, but has refused to rule out campaigning for Britain to return to the EU in the long term.
During the leadership race he pledged to raise income tax for the top 5% of earners, to campaign for EU freedom of movement to continue and to push for "common ownership" of public services such as mail, rail and energy.
He has also vowed to introduce a Prevention of Military Intervention Act if he becomes PM, to ensure Britain could only go to war if the Commons agreed.
Sir Keir lost his mother-in-law during the leadership race, but despite the personal challenges, his campaign retained momentum throughout.
He is married to Victoria, a solicitor, and the couple have two children.