A series of civil wars surrounding the ascension of the nine-year-old Byzantine emperor John V Palaiologos greatly benefited Orhan. In the Byzantine civil war of 1341–1347, the regent John VI Kantakouzenos married his daughter Theodora to Orhan and employed Ottoman warriors against the rival forces of the empress dowager, allowing them to loot Thrace. In the Byzantine civil war of 1352–1357, Kantakouzenos used Ottoman forces against John V, granting them the use of a European fortress at Çimpe around 1352. A major earthquake devastated Gallipoli (modern Gelibolu) two years later, after which Orhan's son, Süleyman Pasha, occupied the town, giving the Ottomans a strong bridgehead into mainland Europe.