This historical party monograph is dedicated to the heroic struggle of the Soviet people that unfolded on the territory of the Leningrad Region during the Great Patriotic War - in the rear of the Nazi Army Group North. The book pays great attention to the party leadership of the partisan movement, shows how the Leningrad Regional Committee of the CPSU (B.) Directed the nationwide struggle against the Nazi invaders, created and built its organizations in the territory occupied by the enemy, as the Communists led a massive armed uprising of the population against the invaders.