The Polish Hussars (/həˈzɑːr/, /həˈsɑːr/, or /hʊˈzɑːr/; Polish: Husaria [xuˈsari.a]), or Winged Hussars, were one of the main types of the cavalry in the Polish-Lithuanian Commonwealth between the 16th and 18th centuries. When this cavalry type was first introduced by the Serbian and Hungarian mercenary horsemen at the beginning of the 16th century, they served as light cavalry banners in the Polish army; by the second half of the 16th century and after Stephen Báthory's reforms, hussars had been transformed into heavily armored shock cavalry. Until the reforms of the 1770s, the husaria banners were considered the elite of the Polish cavalry. When Bathory was elected King of Poland and later accepted as a Grand Duke of Lithuania in 1576, he reorganized the hussars of his Royal Guard into a heavy formation equipped with a long lance as their main weapon. By the reign of Batory (1576–1586), the hussars had replaced medieval-style lancers in the Polish Crown army, and they now formed the bulk of the Polish cavalry. By the 1590s, most Polish hussar units had been reformed along the same "heavy" model. These heavy hussars were known in Poland as Husaria. Between then and the Battle of Vienna in 1683, the Hussars fought many battles against various enemies, most of which they won.