Who was the king of England in 1773?

King George III (Reigned 1760 to 1820)

George III began his reign as King of the United Kingdom of Great Britain. He also held the separate title King of Ireland.

During his reign, on 1st January 1801, the crowns of Great Britain and Ireland were united and he became King of the United Kingdom of Great Britain and Ireland.

The title, "King (or Queen) of England" has not existed since 1707.