 With his enlarged army Petar II advanced to the south, surprised and defeated the Byzantine Emperor Michael IV the Paphlagonian at Thessaloniki taking his treasury.One of Michael's commanders the Bulgarian Manuel Ivats, probably a son of Samuil's boyar Ivats joined Peter II.After the victory the Bulgarian troops under the "voivoda" Kavkan captured Dyrrachium on the Adriatic Sea and some forces penetrated deep into Thessaly eventually reaching Corinth.