THE DEMISE OF HEAVY ARMORED CAVALRY
New weapons and tactics increasingly began to threaten the heavy cavalry’s military supremacy. Under England's Edward III, well-trained, mounted longbowmen, who dismounted to fight, were used extensively, giving their armies mobility and deadly firepower. English knights also accelerated the practice of dismounting and fighting on foot, while their massive chargers waited calmly in the rear in case they were needed for retreat. Such strategies would prove decisive in the great English victories over the French at Creacutecy (1346) and Agincourt (1415) during the Hundred Years’ War.
Cannons, firearms, and more efficient and powerful crossbows became ever more important in the 15th century, as their missiles could penetrate all but the best armor. The emergence of larger standing armies using effective and well-trained infantry pikemen also undermined the significance of heavy cavalry. Together, these factors conjoined to create a revolution in medieval warfare – a revolution that saw the end of the dominance by heavy, armored cavalry over infantry.
While the destrier was losing his predominance on the battlefield, the tournament was more popular than ever, ensuring the survival of many outdated accoutrements of war, including the great medieval warhorse. Though no longer needed in large numbers for battle, the destrier survived as an object of esteem and sport.