Horvat was the brother of Ladislaus and Paul, Bishop of Zagreb, and nephew of John of Palisna. Together with his uncle, Horvat led the uprising against Queen Mary and her mother and regent, Elizabeth of Bosnia. He assisted King Charles III of Naples in deposing Mary and assuming the Hungarian crown in late 1385. Queen Elizabeth soon had Charles murdered. In 1386, Horvat and his uncle captured the queens in Gorjani and imprisoned them. Elizabeth was strangled on the orders of Horvat's uncle, while Mary was eventually released by her husband, Sigismund of Luxembourg, who had recently been crowned king of Hungary. Horvat's ally was Elizabeth's first cousin, King Tvrtko I of Bosnia, who appointed him and his brothers governors of Usora. Horvat himself was also granted the city of Omiš by King Tvrtko. However, Tvrtko died in 1391 and three years later, Horvat was captured by King Sigismund. Sigismund and Mary then avenged her mother's death by having Horvat brutally executed in Pécs on 15 August 1394.
References
Engel, Pal; Ayton, Andrew; Pálosfalvi, Tamás (1999). The realm of St. Stephen: a history of medieval Hungary, 895–1526 Volume 19 of International Library of Historical Studies. Penn State Press. ISBN0-271-01758-9.
Fine, John Van Antwerp (1994). The Late Medieval Balkans: A Critical Survey from the Late Twelfth Century to the Ottoman Conquest. University of Michigan Press. ISBN0-472-08260-4.