The area was populated by Finnic peoples. In the 14th-15th centuries, during the colonization, it was a disputed territory between the Grand Duchy of Moscow and the Novgorod Republic. Novgorod controlled a major part of the Russian North, and, in particular, all areas along the Sukhona River northeast of what is now Nikolsky District. Moscow controlled Veliky Ustyug, which it inherited from the Vladimir–Suzdal Principality, while the Yug River was the waterway it used to get to Veliky Ustyug. It is known that in 1425 Nikolsk and surrounding territories paid tribute to Novgorod. In the end of the 15th century, the Grand Duchy of Moscow took over the Novgorod's territories and Nikolsk became one of the key points on the way from Moscow to the White Sea, which until 1703 was the main route for the foreign trade in Russia. The harbor of Nikolsk in particular was used to transport cargo.
