Bolko (Bolesław) I the Strict, also known as Bolko (Bolesław) of Jawor, was a Duke of Lwówek (Löwenberg) 1278–81 and Jawor (Jauer) after 1278, sole Duke of Lwówek after 1286, Duke of Świdnica-Ziębice from 1291.

Bolesław II the Horned, known also as Bolesław II the Bald, a member of the Silesian Piasts, was High Duke of Poland briefly in 1241 and Duke of Silesia at Wrocław from 1241 until 1248, when the duchy was divided between him and his brothers. After the partition, he ruled the Silesian Duchy of Legnica until his death. The second Mongol raid against Poland, led by Nogai Khan, occurred during his reign.