The advance of Christian forces in Ottoman territory also encouraged the peoples of the Balkan Peninsula to revolt in periferies of the Ottoman Empire. For instance, Skanderbeg, an Albanian noble, expelled the Ottomans from Krujë and all other fortresses once held by his family. Sultan Murad II, whose main concern was a rebellion by the Karamanids in Anatolia, offered generous terms of peace to King Vladislaus. He even promised to withdraw the Ottoman garrisons from Serbia, thus restoring its semi-autonomous status under Despot Đurađ Branković. He also offered a truce for ten years. The Hungarian envoys accepted the Sultan's offer in Edirne on 12 June 1444.