 A war with Serbia in 1331 – 1334 proved less successful for the Emperor when several towns in Macedonia were captured by the Serbs, led by the renegade Syrgiannes Palaiologos. These gains were only curtailed when the assassination of Syrgiannes and the threat of a Hungarian invasion forced the Serbian ruler, Stefan Dušan, to seek a negotiated settlement. The subsequent peace treaty concluded between Andronikos III and Dušan was important for the future of Byzantine-Serbian relations. For the first time, the Byzantines recognized the extensive gains the Serbs had made at the Empire's expense in the central Balkans during Andronikos II's reign. In the aftermath of the pact, Dušan also moved his seat, and with it his realm's centre of gravity, south to Prilep.
