In April 1398 Helen was dethroned in favour of Ostoja (, 1409-1418). Documents often identify him as Ostoja Kristić, which led early historians (including Orbini) to claim that he was not a Kotromanić. It has become accepted, and corroborated by historical documents, that the Kristići were a cadet branch of the Kotromanić family. Ostoja himself emphasised he derived his right to the Bosnian crown from his royal parentage. He immediately repudiated his commoner wife, Vitača, and married Kujava Radinović, a member of a Bosnian noble family. His relationship with the magnates, primarily Hrvoje Vukčić Hrvatinić and Sandalj Hranić Kosača, fluctuated. In 1404 Ostoja was dethroned by the magnates and replaced with Tvrtko II, a son of Tvrtko I whose legitimacy is disputed. Tvrtko reigned as a puppet king until Ostoja was reinstated in 1409. A violet conflict with his in-laws in 1415 led Ostoja to repudiate Kujava too. His third wife, Jelena Nelipčić, brought a considerable part of the Hrvatinić land to the Kotromanić royal domain in 1416. Ostoja died in 1418, leaving a legitimate son by Kujava, Stephen Ostojić (), who succeeded him, and two illegitimate sons, Radivoj and Thomas.