During the chaos that surrounded Lazar's death and the split in the provisional regency, King Stjepan Tomaš of Bosnia attacked the Despotate's holdings west of the Drina river and conquered most of them, leaving only Teočak in the Despotate's hands. Mihail Silagyi likewise seized most of Lazar's towns north of the Danube. Immediately after Mihailo Anđelović's failed coup, the Ottomans began another invasion of Serbia. Although they would not make any significant territorial gains until 1459, this was the beginning of the end for the Serbian Despotate. Stefan Branković ruled until 8 April 1459, when he was overthrown by a plot between Helena Palaiologina and King Tomaš, whose son briefly ruled as the new Despot.