Commonwealth realm
Although King Charles III is monarch of many countries, the British government has no power in the other realms, just as the governments of the other realms have no power in the UK. This is why each realm decides on the Monarch's official title. Usually it is "Queen/King of (realm) and Her/His other Realms and Territories, Head of the Commonwealth". But two countries mention the UK in their title for the Queen: Grenada uses "Queen of the United Kingdom of Great Britain and Northern Ireland and of Grenada and Her other Realms and Territories, Head of the Commonwealth", while Canada uses the old-fashioned form, which reads "by the Grace of God, of the United Kingdom, Canada and Her other Realms and Territories Queen, Head of the Commonwealth, Defender of the Faith." Not all countries use the title Defender of the Faith.