The end of Seuthopolis is a matter of debatte, but it is clear that the town was destroyed still in the first half of the 3rd century. According to some scholars it was conquered by the Celts in the 270s. The Celts were ravaging much of the Balkan Peninsula since the early 270s and also led numerous incursions into Thrace. In 278 and led by Comontorius, they eventually founded a kingdom in eastern Thrace centered around Tylis. A newer theory proposes the destruction of the town in the 250s, based on a revamped dating of pottery, numismatic evidence and the presence of several Celtic artefacts. The archaeolgical evidence also shows the employment of siege artillery, which is unlikely to have been utilized by Celts. It may therefore be that Seuthopolis was not destroyed by the Celts, but by the Seleucid king Antiochus II, who campaigned in the Thracian interior in around 252.