George IV (George Augustus Frederick) was King of the United Kingdom of Great Britain and Ireland and of Hanover following the death of his father, George III, on 29 January 1820, until his own death ten years later. From 1811 until his accession, he served as Prince Regent during his father's final mental illness.
The royal style of King George IV was "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".
The title King of Gibraltar continues to be used by Spanish monarchs even though the territory was ceded to the Crown of Great Britain in perpetuity under the terms of the Treaty of Utrecht of 1713. The continued use of the title thus emphasizes a Spanish viewpoint that the British monarch merely has possession of Gibraltar, rather than sovereignty over it. The United Kingdom, by contrast, takes the position that the treaty transferred sovereignty as well as possession. It was customary for titles and arms of conquered territories to be omitted from British regnal claims. The title and arms were thus never claimed by the British monarchy.