Soon after arriving in London, a foreign Ambassador has an audience with The Queen.

This is a formal ceremony in which a newly-appointed foreign Ambassador or High Commissioner presents his or her Letters of Credence or Letters of High Commission to Her Majesty.

The Ambassador is collected from the Embassy or residence by a State landau from the Royal Mews.

He or she is escorted by the Marshal of the Diplomatic Corps, who is based at St. James's Palace. The Ambassador's suite follows in another State landau.

During the 20-minute audience, the Ambassador presents his or her Letters of Credence or Letters of Commission and his or her suite is presented to The Queen.

The Ambassador's party then returns to the Embassy or residence by carriage.

The State landaus which are used can be seen in the Royal Mews behind Buckingham Palace. All of them date before 1872.

In 1886 there were only six Ambassadors in London, with 37 other countries represented by Ministers.

Today, there are 172 Foreign Missions. They are accredited to the Court of St James's in London, because St. James's Palace is still the senior palace and official residence of the Sovereign.

In the UK, representatives from countries in the Commonwealth are known as high commissioners rather than ambassadors.