Martin McGuinness

A former IRA commander in Derry, McGuinness became Sinn Féin's chief negotiator in the 1990s and then Northern Ireland's deputy First Minister from 2007 to 2017. His unlikely working relationship with Ian Paisley earned them the nickname 'the Chuckle Brothers' and showed the institutions could function. In 2012 he shook hands with Queen Elizabeth II in Belfast. His resignation in January 2017, over a renewable heating scandal, collapsed power-sharing for three years, shortly before his death.