The Normans brought the name to England in the 11th century but it quickly died out. It was reintroduced by the German House of Hanover when they inherited the British throne in the 18th century. A famous bearer was Frederick Douglass (1818-1895), an American ex-slave who became a leading advocate of abolition.
This was the name of kings of England, Serbia, and Poland, as well as ten popes. It was also borne by the first Christian king of Hungary (11th century), who is regarded as the patron saint of that country. More recent bearers include British physicist Stephen Hawking (1942-2018) and the American author Stephen King (1947-).