The tank’s earliest predecessors can be traced back to horse-drawn war chariots of the 2nd millennium BCE in the Middle East and, later, to the protected vehicles of the Middle Ages in Europe. Both ideas fused in the 14th and 15th centuries when Guido da Vigevano and Leonardo da Vinci developed battle cars. However, more practical forms emerged in early 20th century England with the first self-propelled armoured vehicle—an armoured steam traction engine—and the first motor vehicle mounted with a machine gun. The operational push to develop such vehicles arose from the vulnerability of horse-drawn carriages in the infantry, which were needed to improve the mobility of the heavy machine guns that dominated battlefields.