In 74-65 BC, for the first time the Roman army of Gaius Julius Caesar advanced to the north of the Balkan Mountains. The province of Moesia was formed. Defence facilities were built, as well as roads and fortresses. At about 500 m away from the village of Krushuna, the fortresses Kaleto and Daran-baran (from Turkish Dari-ambaria). They were a good defence against invading tribes from the north-Goths, Carpi, Sarmatians, Vandals and others. Both fortresses were part of one system. Dari-ambari was the front side of the fort which houses the guards. The western side is natural and the rest is surrounded by a wall, whose foundations have been preserved ever since. In the region, many Roman coins, fragments of pottery, bricks, Roman plaque: “Evteator posferum” were found. As a fundament of a column in the church St. Theodore the Tryon in Letnitsa, a Roman capital is located, turned upside down, with the inscription “Alexander ...” probably a Roman general, from the time of Trajan and many others.

In the VI-VII century, the lands were populated by Slavs and proto-Bulgarians.