Decline of Cavalry in Western Europe
The role of cavalry had declined in the Spanish army because the Spaniards had increased their infantry partly at the expense of it. Since a properly armored heavy cavalryman could cost four times as much as a pikeman or arquebusier, a small decrease in heavy cavalry could finance a huge addition to the infantry and bring about a dramatic alteration in the proportions between infantry and cavalry. Though a large part of their cavalry consisted of traditional full-armored lancers, the Spanish did have cavalry that performed a light cavalry’s strategic duties of reconnaissance and attack on the enemy’s stragglers, foragers, convoys, and logistic installations. Usually mounted arquebusiers filled this role. Because of the difficulties involved in using the arquebus while mounted, these horse arquebusiers were really mounted infantry. They usually dismounted to use their weapons. But on at least one occasion, after the battle of Ceresole in 1544 [C.E.], mounted arquebusiers pursued retreating heavy infantry and, by dismounting to shoot and remounting to continue the pursuit, managed effectively to simulate the traditional Parthian or Turkish tactics of light cavalry.
The rest of western Europe copied this change from the Spanish, leading to the permanent decline of “pure” cavalry in warfare there.