United Kingdom / King Charles III

King Charles III (Charles Philip Arthur George) is King of the United Kingdom and 14 other Commonwealth realms. He acceded to the throne on 8 September 2022 upon the death of his mother, Queen Elizabeth II. As Duke of Cornwall and Duke of Rothesay from 1952 to his accession, he was the oldest and the longest-serving heir apparent in British history, and the longest-serving Prince of Wales, having held the title from 26 July 1958 until his accession. At 73, Charles was also the oldest person ever to assume the British throne. The record was previously held by King William IV at age 64.

Charles was born in Buckingham Palace, the first child of his mother and Philip, Duke of Edinburgh; he was the first grandchild of King George VI and his consort, Queen Elizabeth. He was educated at Cheam and Gordonstoun schools, both of which his father attended as a child. He later spent a year at the Timbertop campus of Geelong Grammar School in Victoria, Australia. After earning a Bachelor of Arts degree from the University of Cambridge, Charles served in the Royal Air Force and Royal Navy from 1971 to 1976.

In the United Kingdom King Charles III is styled: "His Majesty Charles the Third, by the Grace of God, of the United Kingdom of Great Britain and Northern Ireland and of His other Realms and Territories King, Head of the Commonwealth, Defender of the Faith" in English, and "Charles y Trydydd, drwy Ras Duw, ar Deyrnas Unedig Prydain Fawr a Gogledd Iwerddon a’i Deyrnasoedd eraill, yn Frenin, yn Ben ar y Gymanwlad, yn Amddiffynnwr y Ffydd" in Welsh.

The title "Defender of the Faith" reflects the Sovereign's position as the supreme governor of the Church of England. The original Latin phrase Fidei Defensor is represented on all current British coins by the abbreviations F D or FID DEF.

The monarch, besides reigning in the United Kingdom, separately serves as monarch for a number of other Commonwealth countries known as Commonwealth realms. This developed from the former colonial relationship of these countries to Great Britain, but they are now independent of each other and are legally distinct.