United Kingdom / King George III

George III (George William Frederick) was King of Great Britain and Ireland from 25 October 1760 until the union of the two countries on 1 January 1801, after which he was King of the United Kingdom of Great Britain and Ireland until his death. He was concurrently Duke and prince-elector of Brunswick-Lüneburg ("Hanover") in the Holy Roman Empire until his promotion to King of Hanover on 12 October 1814.

The royal style of King George III as King of the United Kingdom (after 1801) was:

"By the Grace of God, of the United Kingdom of Great Britain and Ireland King, Defender of the Faith, Arch-treasurer and Prince-Elector of the Holy Roman Empire, Duke of Brunswick-Luneburg".

This reflected the United Kingdom created by the Acts of Union 1800 and shed the more than 300-year-old pretense to the throne of France. In 1814, it was changed to:

"By the Grace of God, of the United Kingdom of Great Britain and Ireland King, Defender of the Faith, King of Hanover, Duke of Brunswick-Luneburg".