Pre-Doomsday, the area that constitute the modern borders of Karelia had been taken from Finland during the Winter War in 1939. In 1941 Karelia was re-conquered for three years during the Continuation War 1941-1944 when East Karelia was also occupied by the Finns. The Winter War and the resulting Soviet expansion caused considerable bitterness in Finland, which lost its second biggest city, Viipuri, its industrial heartland along the river Vuoksi, the Saimaa canal that connected central Finland to the Gulf of Finland, access to the fishing waters of Lake Ladoga (Finnish: Laatokka), and made an eighth of her citizens refugees without chance of return.