Edward Fitzgerald, Duke of Leinster was Ireland's premier peer of the realm. In the early twentieth century, he unexpectedly inherited the dukedom following the deaths of his two older brothers. An addicted gambler, he had already signed away his rights to the family's ancestral seat, Carton House, near Maynooth, Co. Kildare in Ireland, never expecting that he would actually inherit the property and his title. He moved to live in England.

It was revealed in 2003 that, though a close friend of King Edward VIII, he was the third lover of the King's mistress Wallis Simpson during the Abdication Crisis in 1936.