Sir Steel was created by Roy Thomas and Frank Robbins in 1976 and first appeared in The Invaders # 7.
Sir Steel was a member of the World War I team Freedom's Five. Prior to the war he had been the manor blacksmith on the Armatage Estate, which was where he met his sidekick Silver Squire. It is unclear how he came into possession of his enchanted blade, although it was believed that his weapon had been passed on to the Templar, a member of the First Line. This made people assume that the two where perhaps related, but there is no information to back up this theory. It is known that he died during the influenza epidemic of 1919, as noted by the original Union Jack in his notes.