All six living former Prime Ministers stood together for the first time at the King’s accession council today.
Boris Johnson, Theresa May, David Cameron, Gordon Brown, Tony Blair and Sir John Major appeared at the solemn event, to see King Charles proclaimed the new head of state.
Mr Brown and Mr Johnson chatted before the ceremony began, while Mr Cameron and Mrs May also chatted at St James’ Palace this morning.
Also attending the ceremony were former Labour leaders Ed Miliband and Neil Kinnock, Mayor of London Sadiq Khan, Lib Dem leader Sir Ed Davey, former Deputy Prime Minister Nick Clegg , former Lib Dem leaders Sir Vince Cable and Lord Campbell and former Tory leaders Sir Iain Duncan Smith, Lord Hague and Sir Michael Howard.
Jeremy Corbyn, who was sworn of the Privy Council in 2015, is not thought to have attended the ceremony.
Aside from Mr Corbyn every living Labour and Tory leader was in attendance.
Senior ministers, many of whom were also in attendance at the event, will later travel to Buckingham Palace for an audience with the monarch.
Ms Truss, who was invited to form a Government by the late Queen on Tuesday, had her initial audience with the King on Friday.
The Prime Minister curtsied as she was ushered in by a Palace aide for the first of what will be their regular weekly encounters.
As she offered her condolences, the King shook her hand and thanked her, saying: "You are very kind for coming - I know how busy you are."
He added: "But it's been so touching this afternoon when we arrived here, all those people come to give their condolences."
Ms Truss again repeated: "Your Majesty, my very greatest sympathies."
He replied: "You are very kind. It was the moment I have been dreading, as I know a lot of people have. We'll try to keep everything going. Come, come have a seat."
Earlier, the Prime Minister had led tributes in the House of Commons to the Queen as she urged the country to support their new monarch.
