Godfrey of Bouillon was a medieval knight who was a leader of the First Crusade from 1096 until his death. He was the Lord of Bouillon, from which he took his byname, from 1076 and the Duke of Lower Lorraine from 1087. After the fall of Jerusalem in 1099, Godfrey became the first ruler of the Kingdom of Jerusalem, although he did not use the title "king."

He was the second son of Eustace II, Count of Boulogne, and Ida of Lorraine .