When Emperor Diocletian divided the province of Dacia into Dacia Ripensis (on the banks of the Danube) and Dacia Mediterranea, Serdica became the capital of Dacia Mediterranea.
Da kejser Diocletian delte provinsen Dakien i Dacia Ripensis (ved bredden af Donau) og Dacia Mediterranea, blev Serdica hovedstad i Dacia Mediterranea.