After the death of his father in 1364 Bolesław and his siblings (three brothers: Rupert I, Wenceslaus II, and Henry VIII and one sister, Hedwig) were placed under the guardianship of their uncle Louis I the Fair.

Like his brothers Wenceslaus II and Henry VIII, Bolesław IV was destined to the Church since his early years, in order to prevent further divisions of the already small Duchy of Legnica.

In addition, on 2 December 1372 the brothers signed an agreement which declared the indivisibility of the duchy for the next ten years.

However, by 1373 Bolesław IV decided to leave his clergy career and also made his resignation over the actively government of Legnica.

Bolesław IV died without issue between 3 and 4 March 1394, as a result of a fatal wound during a tournament.