However, most likely Sineus never existed,[6] and the earliest archaeological data in or around Belozersk belong to the 10th century. In the 10th-13th centuries the area was controlled by the Novgorod Republic, then in the 13th century it was part of the Principality of Beloozero, and in the 14th century it entered the Grand Duchy of Moscow. The Mariinsk Canal system was constructed in the early 19th century, and after the reconstruction in the 20th century it became the Volga–Baltic Waterway.