An alliance with Bulgaria failed to secure any gains for the Byzantine empire. On 28 July 1330, the Serbians decisively defeated the Bulgarians in the Battle of Velbazhd (modern Kyustendil, Bulgaria) without significant Byzantine participation. The Ottomans continued to advance in 1331, finally taking Nicaea (İznik). Andronikos III wanted Nicomedia and the other few Byzantine forts in Anatolia not to suffer the same fate and sought to pay off the Ottomans with tribute.