Velikiye Luki Oblast
On 2 October 1957 Velikiye Luki Oblast was abolished. Its area was split between Kalinin and Pskov Oblasts. Belsky, Ilyinsky, Leninsky, Nelidovsky, Oktyabrsky, Penovsky, Seryozhinsky, Toropetsky, and Zharkovsky Districts were transferred to Kalinin Oblast, and all other districts were merged into Pskov Oblast. On 29 July 1958 Ploskoshsky District was transferred from Pskov to Kalinin Oblast, which finally set the current borders of Tver Oblast.