Queen Elizabeth II attended a cabinet meeting on Tuesday to mark her diamond jubilee, in the first such visit by a monarch in more than a century.
Prime Minister David Cameron greeted the 86-year-old sovereign on the steps of 10 Downing Street as she arrived for the gathering of senior government ministers.
The queen was to receive a diamond jubilee gift from the cabinet to mark her 60 years on the throne, and will also sit in on their meeting as an observer, Buckingham Palace said.
Historically, monarchs used to chair cabinet meetings but the last one to exercise their right to attend was queen Victoria, Queen Elizabeth’s great-great grandmother, who died in 1901.
Cabinet meetings usually last around an hour and a half but the queen will attend for 30 minutes, before leaving with Foreign Secretary William Hague for a visit to the Foreign Office, which is on the other side of Downing Street.
The queen will sit in the middle of the table, with Cameron to her right and Hague to her left.
The green, boat-shaped table was introduced by Harold Macmillan, who served as prime minister from 1957 to 1963, to allow him to see all his ministers.
Queen Elizabeth has been to Downing Street on numerous occasions during her reign, most recently in July for a diamond jubilee lunch hosted by Cameron and attended by former prime ministers Gordon Brown, Tony Blair and John Major.
Twelve British premiers, the first being Winston Churchill, have served during her 60-year reign.
But she has never attended a cabinet meeting, where secretaries of state discuss the big issues of the day.
“The monarch used to chair cabinet, historically. They no longer do but there is no constitutional bar to attending cabinet, although that right has not been exercised recently,” a Buckingham Palace spokesman told AFP.
Though Queen Elizabeth is Britain’s head of state, her role in exercising power is largely formal and the monarchy has to remain strictly neutral in political affairs.
She gives a weekly audience to the prime minister at which she has a right and a duty to express her views on government matters. No-one else is present, no notes are taken and the content is never discussed.