The book is dedicated to the events of the Great Patriotic War in the seas of the Arctic Ocean, which until now have been fully known only to a narrow circle of specialists. The book describes in detail the role of the Arctic theater of military operations and the place of the Soviet Northern Fleet in ensuring the security of allied convoys. Based on documents and memories of participants in the events, the author talks about the famous operation of the German Navy “Wunderland” and explains the reasons for its failure. The book tells about the heroism of Soviet sailors and polar explorers, collisions of battleships and aircraft carriers in the Arctic, shows the reasons for the failures and successes of allied convoys, analyzes the failed attempts of the Germans to create a network of weather stations in the polar archipelagos, and also talks about the fight against German submarines on the Northern Sea Route and about much more.