His Epitaph, which was written in the middle of the 11th century, emphasized that Bolesław had been born to a "faithless" father and a "true-believing" mother, suggesting that he was born before his father's baptism.
Epitafnya, yang ditulis pada pertengahan abad ke-11, menekankan bahwa Bolesław telah lahir dari seorang ayahanda "yang kafir" dan seorang ibunda "yang beriman", menunjukkan bahwa ia lahir sebelum pembaptisan ayahandanya.