He had two brothers, including prelate Nicholas, and a sister, the wife of Alexander Aba, progenitor of the Nekcsei family.
One of Ladislaus' three sons from his unidentified wife was Ladislaus III, voivode of Transylvania (1295–1314) who became one of the most powerful oligarchs during the interregnum after the death of king Andrew III and ruled Transylvania de facto independently until his death in 1315.
[4] In 1263, he led a Hungarian army in alliance with a Bulgarian magnate, Jacob Svetoslav against the re-forming Byzantine Empire.
However, along with his brother Julius, he defected to Béla IV in 1264, and led a campaign through the valley of river Maros (Mureș) to invade Transylvania, nevertheless he suffered a serious defeat from the army of Peter Csák at the Fortress of Déva, which functioned as the "royal castle" of Stephen.
This reduction in political power is demonstrated by the fact that he was able to holding an office only after the sudden death of the king, when he served as ispán (comes) of Pozsony County between 1272 and 1273.