After the collapse of Rome Europe was dominated by relatively small powers. Its development, therefore, was different from that of China or some of the powers of the Middle East. Lacking continuous existence and permanent facilities armies depended on native skills which recruits brought with them. The retinues of the powerful, who could train and buy equipment, were at an advantage. In time they became predominantly mounted warriors, the knights. Infantry were never a negligible force, but without training they lacked the coherence to make their mass effective. In the later Middle Ages standing armies in Europe grew out of rising prosperity, the improving structures of a few states and the demands of continuous warfare. By contrast Mamluk Egypt developed a standing army by about 1240, while China always had one. The Mongols, by virtue of their way of life with its ‘native skills’, constituted a permanent army. Although improved metallurgy increased the supply of better weapons and armour, and experience in stonework led to better fortifications, the technology of war changed little. War remained up close and personal, an affair of plundering and, when battle became necessary, close-order formations fighting at close-quarters. Gunpowder, therefore, was a major challenge whose impact on war before the mid 15th century was limited.