The Queen attended a meeting of the cabinet of the British government today, one of the final diamond jubilee events of the year.
Dressed in a royal blue coat, the Queen walked up the red carpet on the steps of No. 10 before standing chatting with the prime minister at the door to pose for photographs.
She is believed to be the first monarch to atend a cabinet meeting since King George III. A former Cabinet Secretary said it was a testimony to the Queen's neutrality that Prime Minister David Cameron felt able to invite a monarch into the UK's decision-making body for the first time in hundreds of years.
Monarchs have rarely attended Cabinets in the modern era. George III attended once in 1781 to discuss relations between Britain and France but the last time a monarch went regularly was when George I chaired the cabinet in 1717. George VI also once went to the war cabinet during World War II.
In honour of the Queen's visit, secretaries of state conducted a ministerial whip-round and bought her a gift, a set of place mats. The BBC reported that ministers all chipped in an equal amount.
The Queen, who arrived just after 10am, was attending as an observer and stayed for around half-an-hour at the meeting, which lasted approximately 90 minutes. She sat between Cameron and the foreign secretary, William Hague.
"This has been long-planned as part of diamond jubilee celebrations," the prime minister's spokesman said.
The prime minister visits the Queen weekly for an audience where he updates her on events, while she is also expected to give formal approval of ministerial decisions at meetings of the Privy Council.
The Queen plays a central ceremonial role in the state opening of parliament, when she travels by horse-drawn coach to the House of Lords to read out a speech prepared by ministers announcing details of their legislative plans. She also retains the power to appoint the prime minister.
It is not often that the sovereign sets foot inside No 10. In July, Cameron is believed to have become only the sixth prime minister to extend a social invitation to the Queen when he asked her and the Duke of Edinburgh to a lunch with four of the 12 prime ministers to have served during her 60-year reign