[8] The area was settled in the prehistory, and, as the Western Dvina always has been an important waterway, there are multiple archaeological sites in the district.

Subsequently Porechye developed as an important trading post since it was located at the intersection of roads connecting Saint Petersburg with Kiev and Moscow with Riga.

Later, it lost its trade important, since the Kasplya became more shallow, and the railway between Moscow and Riga went via Velikiye Luki, far from Porechye.

[14] On 12 July 1929, governorates and uyezds were abolished, and Demidovsky District with the administrative center in Demidov was established.

[13] On 12 July 1929, Kasplyansky District with the administrative center in the selo of Kasplya was established as well in the areas which previously belonged to Demidovsky, Dukhovshchinsky, and Smolensky Uyezds.

[13] One more district established on 12 July 1929 was Prechistensky with the administrative center in the selo of Prechistoye.

It was created in the areas which previously belonged to Belsky, Demidovsky, and Dukhovshchinsky Uyezds.

[13] On 12 July 1929 Slobodskoy District with the administrative center in the selo of Sloboda was also established.

[13] The economy of the district is based on agriculture and timber industry; production of building materials is also developed.

[15] The main agricultural specialization of the district are cattle breeding with meat and milk production.

[16] Paved roads connect Demidov with Smolensk, with Nevel via Velizh, and with Rudnya.

The estate formerly owned by the geographer and explorer of Central Asia Nikolay Przhevalsky in the urban-type settlement of Przhevalskoye, as well as a number of archaeological sites, are designated cultural monuments of federal significance.