Victory at Varna

On the 10th of November, 1444, a cold, bitter day in Bulgaria, Crusader forces were beaten in a decisive victory by the numerically superior Ottoman forces. But what if, the Ottoman forces had been stalemated, perhaps even defeated, and Crusader forces successful.

Point of Divergence
November 10, 1444 - Commanders of the ragtag Crusader army, seeing Ottoman forces approaching, decided to use Hussite Wagenburgs and defensive military tactics to stalemate until a Papal Fleet would sail the army down to Constantinople and push the Ottomans out of Europe. (OTL, King Władysław III of Poland and nobleman John Hyunadi rejected this plan, opting to fight the numerically superior Ottoman forces).