Khālid ibn al-Walīd (592–642) also known as Sayf Allāh al-Maslūl (the Drawn Sword of God), was a companion of the prophet Muhammad. He is noted for his military tactics and prowess, commanding the forces of Medina and those of his immediate successors of the Rashidun Caliphate; Abu Bakr and Umar.It was under his military leadership that Arabia, for the first time in history, was united under a single political entity, the Caliphate. He is one of three military generals in history to remain undefeated in battle.