"Once the mass of the defending infantry become possessed of low moral, the battle is as good as lost."
— Douglas Haig, 20th century British general
The transition into modernity for European warfare was heralded by the resurgence of heavy infantry tactics. Originally an innovation of towns and communities that did not have the resources to field large armies of heavy cavalry, it was discovered that pikes were cheap and could be quite effective with proper training, as evidenced by the defeat of knightly cavalry at Kortrijk in 1302.
Eventually, armies of pikes and crossbows (later supplanted by firearms) would dominate Europe from the early Renaissance onwards, leading later to the famed "pike and shot" formations of the next 2 centuries. Similar tactics were also used contemporaneously in Japan, with the usage of long spears or yari which were then supplemented by archery or guns.