He was the second son of Duke Janusz I of Warsaw and Danutė of Lithuania, a daughter of Kęstutis. In 1409 he was sent by his father at the head of a retaliatory expedition against the Teutonic Order, culminating with the conquest and burning of Działdowo and 14 surrounding villages.
Two years later (1411), as an envoy of the Dukes of Masovia he participated in the act of signing of the Peace of Thorn. In 1412 Bolesław was in Krakow, at the court of King Władysław II Jagiełło, and he, among others princes, traveled with the King to the frontier city of Stará Ľubovňa to a meeting with the German King Sigismund of Luxembourg. Bolesław died unexpectedly after 1420 but certainly before 4 May 1424.
He was buried next to his father at Saint John"s Archcathedral, Warsaw.
