William Joyce was a fascist politician and Nazi propaganda broadcaster to the United Kingdom during World War II. He had citizenship in both the United States and The United Kingdom. Joyce became a naturalized German in 1940.

The name 'Lord Haw-Haw of Zeesen' was coined by the pseudonymous Daily Express radio critic Jonah Barrington in 1939, but this referred initially to Norman Baillie-Stewart. When Joyce became the best-known propaganda broadcaster the nickname transferred to him. Besides broadcasting, Joyce's duties included propaganda among British prisoners of war, whom he tried to recruit into the British Free Corps, as a branch of the Waffen SS. He wrote a book, Twilight over England, that was promoted by the German Ministry of Propaganda.

At the end of the war, he was captured by British forces and tried for treason by broadcasting propaganda. It was then that Joyce's American nationality came to light, and it seemed that he would have to be acquitted. However, Attorney General Sir Hartley Shawcross successfully argued that Joyce's possession of a British passport, even though he had lied about his nationality in order to get it, entitled him to British diplomatic protection in Germany and therefore he owed allegiance to the King. It was on this technicality, confirmed by the Court of Appeal and the House of Lords, that Joyce was convicted and sentenced to death.

Joyce's was executed by famed hangman Albert Pierrepoint on January 3, 1946, at Wandsworth Prison. The Crown considered trying his wife, Margaret, as well, but a secret memo recommended clemency for her.