The Army of the Duchy of Warsaw (Polish: Armia Księstwa Warszawskiego) refers to the military forces of the Duchy of Warsaw. The Army was significantly based on the Polish Legions; it numbered about 30,000 and was expanded during wartime to almost 100,000. It was composed of infantry with a strong cavalry force supported by artillery. The Napoleonic customs and traditions resulted in some social tensions, but are generally credited with helpful modernization and useful reforms.