Complex sentence: As the second son, Władysław was not destined for the throne, however due to the flight from Poland of his older brother Bolesław II the Bold in 1079, he was elevated to the rank of Duke of Poland.
Split into simpler sentences: As the second son, Władysław was not destined for the throne. However, due to the flight from Poland of his older brother Bolesław II the Bold in 1079, he was elevated to the rank of Duke of Poland.