Armor of the Polish Winged Hussars. As the rest of Europe was going for less armor on cavalry due to the emergence of guns in armies, the Poles continued to field cavalry clad in heavy armor. The wings were actually worn into battle and there are many theories as to why.
First is that the Tartars and Cossacks of the Ukraine and Crimea used lassos in battle to lasso and pull down cavalry and the wings prevented that. Another is that the ostrich feathers in the wings made a whistling sound at full gallop which unnerved horses not used to it. A final theory is that is was simply for flamboyance and to strike fear into the opposing army as the Winged Hussars were the premier cavalry in their age.