Accession Council

In the United Kingdom, the Accession Council is a ceremonial body which assembles in St. James's Palace upon the death of a monarch (Demise of the Crown), to formally proclaim the accession of his or her successor to the throne. Under the terms of the Act of Settlement 1701, a new monarch succeeds automatically. The proclamation confirms by name the identity of the heir who has succeeded.

The Council is made up of Privy Counsellors, Great Officers of State, members of the House of Lords, the Lord Mayor of the City of London, the Aldermen of the City of London, High Commissioners of Commonwealth realms, and other civil servants.

The Council's Proclamation of Accession, which confirms the name of the heir, is signed by all the attendant Privy Counsellors. The proclamation is traditionally read out at several locations in London, Edinburgh, Windsor, and York. It may also be read at a central location in a town or village. The most recent proclamation was as follows:

Whereas it has pleased Almighty God to call to His Mercy our late Sovereign Lord King George the Sixth of Blessed and Glorious memory, by whose Decease the Crown is solely and rightfully come to the High and Mighty Princess Elizabeth Alexandra Mary:
WE, therefore, the Lords Spiritual and Temporal of this Realm, being here assisted with these His late Majesty's Privy Council, with representatives of other Members of the Commonwealth, with other Principal Gentlemen of Quality, with the Lord Mayor, Aldermen, and Citizens of London, do now hereby with one voice and Consent of Tongue and Heart publish and proclaim that the High and Mighty Princess Elizabeth Alexandra Mary is now, by the death of our late Sovereign of happy memory, become Queen Elizabeth the Second, by the Grace of God Queen of this Realm and of all Her other Realms and Territories, Head of the Commonwealth, Defender of the Faith, to whom Her lieges do acknowledge all Faith and constant Obedience with hearty and humble Affection, beseeching God by whom Kings and Queens do reign, to bless the Royal Princess Elizabeth the Second with long and happy Years to reign over us.

...
Wikipedia