The last king of Egypt of the Ethiopian (the fifteenth) dynasty. He was the brother-in-law of So (q.v.). He probably ascended the throne about B.C. 692, having been previously king of Ethiopia (2 Kings 19:9; Isaiah 37:9), which with Egypt now formed one nation. He was a great warrior, and but little is known of him. The Assyrian armies under Esarhaddon, and again under Assur-bani-pal, invaded Egypt and defeated Tirhakah, who afterwards retired into Ethiopia, where he died, after reigning twenty-six years.