Stefan Czarniecki (1599–1665) was a Polish military commander who rose from a petty nobleman to a magnate holding one of the highest offices in the Polish–Lithuanian Commonwealth, something that was unprecedented in Polish-Lithuanian history. In 1664 he attained the office of the voivode of Kijów (now Kiev, Ukraine) and in 1665, a few weeks before his death, he became field hetman of the Crown. Czarniecki's major successes came during the Khmelnytsky Uprising in Ukraine, the Russo-Polish War of 1654–67, and the Second Northern War. His use of guerrilla warfare against the Swedes is considered one of the main reasons for the eventual Polish victory in the latter conflict. Czarniecki is regarded as a national hero, his status in Polish history best illustrated by a mention in the national anthem. (Full article...)