In the late 13th century Edward I expanded the "familia regis" to become a small standing army, forming the core of much larger armies up to 28,700 strong, largely comprising foot soldiers, for campaigns in Scotland and France. By the time of Edward III, armies were smaller in size, but the troops were typically better equipped and uniformed, and the archers carried the longbow, a potentially devastating weapon. Cannons were first used by English forces at battles such as Crécy in 1346. Soldiers began to be contracted for specific campaigns, a practice which may have hastened the development of the armies of retainers that grew up under bastard feudalism. By the late 15th century, however, English armies were somewhat backward by wider European standards; the Wars of the Roses were fought by inexperienced soldiers, often with outdated weapons, allowing the European forces which intervened in the conflict to have a decisive effect on the outcomes of battles.