From the Wikipedia page 
Smolensk Oblast (Russian: Смоле́нская о́бласть, Smolenskaya oblast; informal name — Smolenschina (Russian: Смоле́нщина) is a federal subject of Russia (an oblast). Its administrative center is the city of Smolensk.
The oblast was founded on September 27, 1937. It borders Pskov Oblast in the north, Tver Oblast in the northeast, Moscow Oblast in the east, Kaluga Oblast in southwest, Bryansk Oblast in the south, and Mogilev and Vitebsk Oblasts of Belarus, in the west and northwest, as part of the Belarus–Russia border.