Tyr-Us was a powerful and influential Kryptonian, prior to Krypton's destruction. He was the leader of the metal city of Corril in the mountains. He was also the son of Jul-Us, who was the head of the Kryptonian Council before the capital city of Kandor was taken by Brainiac.
During General Zod's emergency provisional government, Tyr-Us was a dissident who opposed Zod and eventually helped to overthrow him.
He later became the new head of the Kryptonian Council. (The Last Days of Krypton)