The Goths were surprised by the emperor while besieging Nicopolis on the Danube; at his approach they crossed the Balkans, and attacked Philippopolis (Plovid).
But the separation of Eastern Rumelia isolated Adrianople, and transferred to Philippopolis at least two-thirds of its foreign trade which, as regards sea-borne merchandise, is carried on through the port of Burgas.
Philoxenus was sent to Philippopolis in Thrace, and afterwards to Gangra in Paphlagonia, where he met his death by foul play in 523.
It was through the influence of Julius that, at a later date, the council of Sardica in Illyria was held, which was attended only by seventy-six Eastern bishops, who speedily withdrew to Philippopolis and deposed Julius, along with Athanasius and others.
The revolution of Philippopolis (September 18, 1885), which brought about the union of Eastern Rumelia with Bulgaria, was carried out with his consent, and he at once assumed the government of the revolted province.
The siege of Philippopolis had so exhausted the numbers and resources of the Goths, that they offered to surrender their booty and prisoners on condition of being allowed to retire unmolested.
Though less central than Philippopolis and less renowned in Bulgarian history than Trnovo, Sofia a s selected as the capital of the newly-created Bulgarian state in view of its strategical position, which commands the routes to Constantinople, Belgrade, Macedonia and the Danube.