Answer
John Jiskra of Brandýs represented Ladislaus's interests in Hungary after his mother's death. Jiskra was a powerful military leader who had previously served as a mercenary for King Władysław II Jagiełło of Poland. After his mother's death, Ladislaus was forced to flee Hungary and take refuge in Poland. Jiskra was able to use his military skills to help Ladislaus regain control of Hungary.