A hajduk (Hungarian: hajdúk, plural of hajdú 'foot-soldier') was initially a type of irregular infantry found in Central, Eastern, and parts of Southeast Europe from the late 16th to mid 19th centuries. Eventually the term was used for armed outlaws. The two categories share a reputation ranging from bandits to freedom fighters, depending on time, place, and their enemies.
In the European lands of the Ottoman Empire, the term hajduk was used to describe bandits and brigands of the Balkans, while in Central Europe for the West Slavs, Hungarians, and Germans, and Eastern Europe for the Ukrainians, it was used to refer to outlaws who protected Christians against provocative actions by the Ottomans. The term originates from Hajdú County of the Kingdom of Hungary.