 On January 29, 1935 Kalinin Oblast was established, and Kalyazinsky District was transferred to Kalinin Oblast.On February 13, 1963, during the abortive Khrushchyov administrative reform, Kalyazinsky District was merged into Kimrsky District, but on March  4, 1964 it was re-established.In 1990, Kalinin Oblast was renamed Tver Oblast.