Bolesławiec (pronounced AUDPl-Bolesławiec.oggbole'sławJec, Bolesławiec, Bunzlau) is a historic city situated on the Bóbr River in the Lower Silesian Voivodeship, in western Poland. It is the administrative seat of Bolesławiec County, and of Gmina Bolesławiec (being an urban gmina in its own right). As of June 2021, it has a population of 38,280. Founded in the 13th century, the city is known for its long-standing pottery-making tradition and heritage Old Town. The name Bolesławiec is derived from the Silesian duke Bolesław I the Tall. The castellany of Bolezlauez in Lower Silesia was first mentioned in a 1201 deed. According to tradition, its citizens took part in the Battle of Legnica during the first Mongol invasion of Poland in 1241. Bolesławiec celebrated its 750th anniversary in 2001. In the Early Middle Ages the region was inhabited by the Bobrzanie tribe, one of the Polish tribes, and it became part of the emerging Polish state under its first historic ruler Mieszko I around 990. A Slavic stronghold was erected in present-day Bolesławiec in the late 9th century. It is now an archaeological site. As a result of the 12th-century fragmentation of Poland into smaller duchies still ruled by the founding Piast dynasty, it formed part of the duchies of Silesia, Legnica and Jawor until 1392. Following the 1241 Mongol invasion, a walled town began to take shape. In 1251, mention is made of Boleslawiec's town charter. Then a part of the Silesian Duchy of Legnica under Bolesław II the Bald, the town from 1297 belonged to the Duchy of Jawor under Bolko I the Strict. In 1316, in order to better protect the townspeople from hostile incursion, new walls were constructed around the town. The city seal, still used today, was also first used in 1316. In 1346, the town joined seven other urban centers in forming the Silesian Association of Fortified Towns. In that same year, the Duchy of Jawor with Bolesławiec was inherited by Duke Bolko II the Small of Świdnica, and upon his death in 1368, it was inherited by Emperor Charles IV, who had married Duke Bolko's niece Anna of Świdnica.