with Sandalj, but took action against the Zlatonosovićs and confiscated their land. Vuk never posed as much threat to Tvrtko as would Radivoj, the elder illegitimate son of the long-deceased Ostoja. In 1432, Stefan Lazarević's successor Đurađ, Sandalj and the Ottomans helped Radivoj lay claim to the throne and take control of much of the country. Tvrtko's only noteworthy support came from Hrvoje's nephew and successor, Juraj Vojsalić, and he thus managed to retain only the central and northwestern Bosnia. Tvrtko retreated to Visoko, but soon found that Sandalj had become too ill to support Radivoj's cause. Đurađ Branković, satisfied with annexing the lands Tvrtko had confiscated from the Zlatonosović family, also lost interest in Radivoj. The Ottomans, however, pursued Radivoj's claim and took possession of Bobovac in his name in 1434. After years of pleading for their help, Tvrtko finally saw Hungarians march into Bosnia in mid-1434. They recovered for him Jajce, Hodidjed, Bočac and the Komotin Castle, but he lost it all as soon as they retreated. In fact, he himself appears to have left with the troops on their way back to Hungary, as he is known to have resided at the court in Buda in 1435. Radivoj ceased being a threat when he lost the Ottoman support that year, while Sandalj's death presented Tvrtko with a new and more vital rebellious vassal in the form of Sandalj's nephew and successor, Stjepan Vukčić Kosača. Later life Radivoj styled himself as King of Bosnia for the remainder of Tvrtko II's reign. He was nominally supported by the Turks and by Stjepan Vukčić Kosača; they could have easily deposed Tvrtko in his favour if they wished, but it appears that their only goal was to weaken and divide Bosnia for their future benefit. While Stjepan was trying to expand his territory at the expense of Zeta in 1443, Tvrtko took advantage of his absence and the Ottoman concern with the Crusade of Varna to attack his land, but Stjepan returned in time to defend it. Tvrtko died childless in November 1443, having expressed wish to be succeeded by his politically inactive and until then rather obscure cousin Thomas, Radivoj's younger brother and likewise an illegitimate son of Ostoja. Hermann II of Celje had died in 1435, and his heirs made no attempt to enforce the 1427 succession agreement. Given that the succession went smoothly, it can be assumed that