Bernard the Lightsome (also known as of Lwówek) (Polish: Bernard Zwinny or Lwówecki ) (ca. 1253/57 – 25 April 1286) was a Duke of Lwówek (Löwenberg) since 1278 (with his brother until 1281) and Jawor (Jauer) during 1278–1281 (as a co-ruler of his brother).
He was the third son of Bolesław II the Bald, Duke of Legnica by his first wife Hedwig, daughter of Henry I, Count of Anhalt. It is not known when exactly he was born but had to happen before 1258, because seven years later he was sent to Wroclaw by his father with the Tithe to the Bishop Thomas.
Bernard actively supported the policy of his father Bolesław II and his brothers, Henry V the Fat and Bolko I the Strict (for example, he participated in the victorious Battle of Stolec). After the death of his father in 1278, Henry V give his younger brothers Bernard and Bolko I the Duchies of Lwówek (Löwenberg) and Jawor as a co-rulers. However, his independent rule began only three years later, in 1281, when he and Bolko made the division of their domains and Bernard received Lwówek. Little is known about this period in Bernard's life, and the only certain fact was (according to the chronicles), that he promoted and protect knights, a common practice among the medieval princes. This also maybe justificated his nickname "Zwinny" (Lightsome, Clever) give to him by contemporarie sources. Lwówek had a special gratitude to him after he kept the Silesian monastery of the Knights Hospitaller, were he was a generous benefactor, giving them among other things in 1281, the village of Cieplice.
Bernard died unmarried and childless in 1286. He was buried in the Dominican church in Legnica, and his lands were inherited by his brother Bolko.
| Preceded by Henry V the Fat |
Duke of Lwówek with Bolko I (until 1281) 1278–1286 |
Succeeded by Bolko I the Strict |
| Duke of Jawor with Bolko I 1278–1281 |