Battle of the Blue Hills
The Battle of the Blue Hills or the Battle of Tannenberg Line, on 25 July-10 August 1944 during WWII, was fought between the Soviet Union and Germany and allies, including many foreign volunteers.
The battle involved a Soviet attempt to conquer the strategically important Narva Isthmus, in order for the Soviet Union to reoccupy Estonia.
The German and allied force of 22,250 men held off 136,830 Soviet troops. As the Soviet forces were constantly reinforced, the casualties were 170,000 Soviet dead and wounded, and 157–164 tanks, against only 10,000 casualties on the German side.
Regardless, later Soviet offensives threatened to encircle the Germans and allies, forcing a retreat.
Some of the Estonianas stayed in Estonia to continue to fight the Soviet occupation, becoming part of the Forest Brothers.