The existence of Christian communities in Scythia Minor became evident under Emperor Diocletian (284–305). He and his co-emperors ordered the persecution of Christians throughout the empire, causing the death of many between 303 and 313. Under Emperor Constantine the Great (306–337), a bridge across the Danube was constructed at Sucidava, a new fort (Constantiana Daphne) was built, and ancient roads were repaired in Oltenia. The Lower Danube again became the empire's northern boundary in 369 at the latest, when Emperor Valens met Athanaricthe head of the Gothsin a boat in the middle of the river because the latter had taken an oath "never to set foot on Roman soil".