Despot Lazar Branković, the only one of Đurađ's sons not to be blinded by the Ottomans, succeeded his father. Sensing that Serbia is too weak to defeat a future Ottoman incursion on the battlefield, he managed to make a deal with sultan Mehmed II on January 15, 1457. According to this deal, he was granted back most of his father's lands and a promise that Serbia will not be disturbed by the Ottomans until Lazar's death. Lazar in turn had to pay a tribute, which was reduced because he no longer had the rich mines of Novo Brdo. Temporarily relieved of the southern threat, Lazar turned to the north and Hungarian internal battles, which he joined on the side of King Ladislaus, managing to capture the town of Kovin and several other towns on the left bank of the Danube in 1457. Lazar suddenly died on January 20, 1458.