Dacia Aureliana was a province of the Roman Empire established by Emperor Aurelian in the territory of former Moesia Superior after his evacuation of Dacia Traiana beyond the Danube in 271. Between 271/275 and 285, it occupied most of what is today northwestern Bulgaria and eastern Serbia. Its capital was in Serdica (modern Sofia). The Emperor Diocletian replaced Dacia Aureliana with two provinces – Dacia Mediterranea with its capital at Serdica and Dacia Ripensis, with its capital at Ratiaria. Later these two “Dacias” along with Dardania, Moesia Prima, and Prevalitana constituted the Diocese of Dacia.