The Battle of Simancas (also called Alhandega or al-Khandaq) was a military battle that started on July 19, 939, in the Iberian Peninsula between the troops of the king of León Ramiro II and Cordovan caliph Abd al-Rahman III near the walls of the city of Simancas. The battle decided the control of the lands of the Duero.The battle unfolded after the army of Abd al-Rahman III launched toward the northern Christian territories in 934.