On this day in 1683, a combined Polish-German army defeats the Ottomans at the Battle of Vienna. The city had been besieged by the Ottoman force for two months when the Christian relief force arrived. The battle is famous as the scene of the largest cavalry charge in history.
After an indecisive infantry engagement, the Christian leaders ordered a massed cavalry charge of nearly 18,000 horsemen, led by the Polish king and his heavy lancers - the famous "winged hussars". The charge broke the Ottoman formation and forced a full retreat.
Defeat at Vienna marked the end of a long period of Ottoman expansion into Europe, and in the following decades Hapsburg forces would reconquer most of Hungary. The victory remains the crowning military glory of Poland.
As a side note, many have noted the similarities between the Polish charge at Vienna and the Charge of the Rohirrim in Lord of the Rings, and it has been suspected that Tolkien (a devout Catholic) drew inspiration from this great Catholic feat of arms.