Pikemen dominated European battlefields after advances in infantry tactics made them effective. Pike and shot was a later development that replaced pure pike sq

Pikemen dominated European battlefields after advances in infantry tactics made them effective. Pike and shot was a later development that replaced pure pike squares long after pikemen had ended the dominance of heavy cavalry. The key development in the pike square was mobility. Earlier infantry forces using similar weapons had more rigid formations, with a single direction that was supposed to point towards the enemy. That made them vulnerable to outflanking by cavalry / skirmishers / archers. Pike squares drilled rapid turns, which made outflanking them much more difficult. The Byzantine Empire remained capable and strong until around 1200, when a series of incompetent emperors destroyed it. In particular, one of them had the clever idea of using the Fourth Crusade in a power struggle against another. That resulted in the loss of Constantinople. While the empire eventually got its capital back, it never recovered. The empire that the Ottomans later defeated was only a shadow of its former self. As for the supposed effectiveness of the Franks and Spaniards: the Reconquista was a series of wars from 718 or 722 until 1492.