[citation needed] Bogusław held the following official positions: He was the son of Rafał Leszczyński, count of Leszno, and Anna Radzimińska.

[2] After the death of his father in 1636 he inherited Leszno, Radzymin and part of Warsawian Praga.

Bogusław married twice, first to Countess Anna Dönhoff, from a prominent Pomeranian family, in 1629 and later to the daughter of Court and Grand Marshal Prince Aleksander Ludwik Radziwiłł, princess Joanna Katarzyna Radziwiłł, in 1658.

During the Swedish invasion of 1655 ("The Deluge"), he was committed by a chapter of the Sejm to defend the province of Greater Poland, but instead Bogusław began to negotiate with the Swedes and the Prussian elector.

A telling story is that when he was offered a Chancellor's post, he bribed the members of the parliament to grant him "absolution", and when one of them later opposed him, he asked, curious: "Who's this son of a bitch that I failed to pay off?"