One of the biggest but not so well explored and presented Roman towns in Bulgaria is Nicopolis ad Istrum. It is located 17 km. north of Veliko Turnovo. The city was built in 2nd century, following the planning of the Roman Empire cities. Some of its so far uncovered features include the bouleuterion or the building where the city council was gathered with dimensions of 15.25/16.60 m., which was found at the central square. The main citizen basilica where law court decisions and some trade deals were made was uncovered as apart of the forum of Nicopolis. The forum itself was surrounded by impressive buildings with astounding architectural details. The city took its fresh water through the stone channel which extends at more than 20 km. in western direction.
In 250 AD Roman Emperor Decius crushed the invasion of the Goths killing more than 30 000 enemies on the field near Nicopolis.
Two early Christian churches (4th-6th century) were found in Nicopolis by a Bulgarian-English archaeological team in the late 1980s. The larger one is with a three sided apse and was dated in the 5th century.
After the city was abandoned in 6th century the bishopry center was moved not far to the south – in a church on the Tsarevets hill in Veliko Turnovo where it probably functioned until the end of 7th century. Some findings on the early Christian church nearby — in Lovech suggest that Christianity was the dominating religion even in the so-called ‘pagan’ period of the earlier Bulgarian state (681-866 AD).