 Despite gaining Golubac , Sultan Murad II was not pleased with the increased Hungarian influence elsewhere in Serbia , so he sent his army to attack . One squad came from Golubac and targeted nearby Serbian and Hungarian settlements in the Braničevo region . In response , Đurađ personally travelled to Golubac , promising forgiveness to Jeremija and urging him to return the fortress by any means possible . The Voivode refused , and attacked the Despot when he and his escort attempted to enter the walls . These betrayals were followed in 1428 by the Battle of Golubac . 
