Horvat was the brother of [[Ladislaus Horvat|Ladislaus]] and [[Paul Horvat (bishop)|Paul]], [[Bishop of Zagreb]], and nephew of [[John of Palisna]]. Together with his uncle, Horvat led the uprising against [[Mary, Queen of Hungary|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 1386. 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 . 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.