He stood as an independent to become the first mayor of London when the powerful post was first created.
In his second term, which he won as the official Labour candidate, he earned praise for the way he stood up for London after the July 2005 suicide bombings and helped the capital win its bid to hold the 2012 Olympic Games.
Mr Livingstone lost control of City Hall in 2008 when he was defeated by Boris Johnson and a failed bid to return to office in 2012 marked the end of his electoral ambitions.
He became embroiled in a string of allegations of anti-Semitism, over which he quit the Labour Party in 2018.
It came after a long-running row over his claims that Adolf Hitler had backed Zionism in the 1930s, which had originally seen him suspended from the organisation in 2016.
Mr Livingstone did not accept he was guilty of anti-Semitism nor bringing Labour into disrepute.
