Jarl is the Scandinavian language cognate of Earl.
In Norse mythology, Jarl was the son of Rig and Modir. Rig taught Jarl runes and other magic, as well as the language of the birds. Jarl then gathered some men and captured some land, then married Erna, with whom he had eleven sons, the ancestors of the warriors in Norse society.
See also: Birger Jarl