Sofia

Sofia, the capital of Bulgaria, occupies a site with nearly 7,000 years of continuous habitation. Known as Serdica in antiquity, it was established by the Thracian Serdi tribe around the 5th century BC in the fertile Sofia Valley. Conquered by Rome in 29 BC, the city flourished as Ulpia Serdica under Emperor Trajan and received fortified walls with towers under Marcus Aurelius around 175 AD. In 311 AD Emperor Galerius issued the Edict of Serdica there, one of the first decrees ending Christian persecution. Archaeological remains including Roman streets, baths, an early Christian basilica, and 4th-6th century houses are preserved in the Serdica Metro Station complex, uncovered during construction from 2010-2012.