Ossorya - is a Polish Coat of Arms. It was used by several szlachta families in the times of the Polish-Lithuanian Commonwealth. The history of Polish heraldry is an integral part of the history of the Szlachta, the Polish nobility. Unlike the case of Western Europe, in Poland, the szlachta did not emerge exclusively from the feudal class of knights under Chivalry, but stemmed in great part from an earlier Slavic class of Free Warriors or Mercenaries. These warriors were often hired by rulers to form guard units (Polish Dru yna) and were eventually paid in land. There is, however, a lot of written evidence from the Middle Ages which demonstrates how some elements of the Polish nobility did emerge from the ranks of the knightly class under the terms of chivalric law (ius militare).