Ladislaus was the only son of King Emeric and his wife, Constance of Aragon. He was crowned on 26 August 1204 while his father was still alive. With the coronation, King Emeric wanted to ensure his son's succession to the throne. Emeric made his brother, Duke Andrew, who had rebelled against the king several times, promise that he would protect the child and help him in the governance until he became an adult. Duke Andrew promised this, and he was appointed to regent during the minority of his nephew.
However, just after his brother's death, Duke Andrew grabbed all power to him and made the life of the little child and his mother hard. Consequently, the Dowager Queen Constance escaped to Vienna to Leopold VI, Duke of Austria with Ladislaus. Ladislaus died in Vienna but was buried in Székesfehérvár.