Steel is the son of the Solamnia knight Sturm Brightblade and the Dragon Highlord Kitiara Uth Matar. He has always been tortured inside by the the nature of both his parents, as they were so different. His father was the image of good, and his mother, evil.
He served the army of Takhisis, but never really felt home there. True, he was a great warrior, but his father's heritage lead him to the light. He wanted to make something good for the world. He did even better: he saved Krynn from the attack of the Chaos itself.
During the Chaos War, he lead a handful of Solamnic knights to their last battle. They were going to the Chaos. He fought with great courage in this battle, and helped to kill the Chaos.
Years later he founded the Knights of Steel, a new order of Knights with a code of honour similar to the Solamnics'.