In the year 1380 he was made Grand Duke of Bosnia by Bosnian King Stjepan Tvrtko I of House of Kotromanić, granting him a seat in Lašva. In 1387 Hrvoje's first action as Grand Duke was leading a squadron of Bosnian troops to Croatia to raise the siege of Bishop Ivan Horvat in Zagreb. After the death of king Louis I he participated in the battles of succession between Sigismund of Luxembourg and Ladislaus of Naples. He sided with Ladislaus with the promise of becoming ban of Croatia and Dalmatia in 1391. During the reign of King Stephen Dabiša of Bosnia, he participated in the fights against the Ottoman Turks in Bosnia in 1392 - earning Dabiša's eternal gratitude. Hrvoje became Dabiša's main guarantee of staying at the throne - as he declared that he is a faithful servant of the Hungarian King in all cases but those that might damage King Dabiša in 1393. In the heat of internal struggles in Bosnia in 1397 during the reign of QueenJelena Gruba Hrvoje invited the Ottomans to offer assistance. As an opposer of Queen Jelena, he participated in the selection of Stephen Ostoja as the new King of Bosnia in May 1398. Opposing King Sigismund's Hungarian pretensions, Hrvoje greatly influenced King Ostoja. coat of arms Duke Hrvoje opposed King Sigismund's rule in Bosnia and actively worked to bring Ladislaus of Naples as the new King of Hungary - that would leave Bosnia alone since 1389, and the same year King Sigismund invaded Bosnia. Duke Hrvoje defeated his forces before they reached the City of Vrbas and chased them across the riverUna, invading and conquering the župa of Dubica. King Sigismund counterattacked in the fall by assaulting Bosnia. Here, Duke Hrvoje led the forces for King Stephen Ostoja, together with Duke Sandalj Hranić and Duke Pavle Radenović. By the end of 1402, Duke Hrvoje made all Dalmatian cities with the exception of Dubrovnik to recognize King Ladislaus' rule. After the crowning of Ladislaus as the Hungarian King in Zadar in 1403, and in political maneuvering against his arch political rival and enemy, the King Sigismund, he made Hrvoje his deputy for Dalmatia territory, as promised, calling him his Vicar General for the regions of Sclavonia. He was also named Duke of Split, and given possessions on the islands of Brač, Hvar and Korčula. From then on he carried the title of "Grand Duke of Bosnia and Knyaz of Donji Kraji, Duke of Split, regent of Dalmatia and Croatia", or as title visible on coins duke was able to mint in Split read in Dux Spaleti, Dalmatie Croatieque regius viceregens ac Bosne supremus vojvoda. In 1406 Hrvoje Vukčić Hrvatinić fortified and strengthen Prozor Fortress over the Vrlika valley in Croatia, also given to him by Ladislaus of Naples. He continually exerted his influence over Bosnia affairs. He came into conflict with King Ostoja and participated in the plot to remove him from the throne and replacing him with Tvrtko II Kotromanić in 1404. Together with Tvrtko II he formed a movement against Hungary and Sigismund of Luxembourg. After Sigismund's military intervention in 1408 and the massacre of the Bosnian army, he allied himself with Sigismund. However, Hungary's victory in Bosnia and the retaking of the throne by King Ostoja weakened him severely. He soon lost control over the islands he had been given, as well as Split. At this point, he sought help from the Ottoman Empire. The Hungarian army was defeated at Lašva in 1415, but this would open the door to Ottoman expansion into Bosnia. Hrvoje died the following year and his widow, Jelena Nelipčić, married King Ostoja.