At the start of the Winter War, the Finnish troops settled in defence positions in December 1939. The defence line was then given the name Mannerheim Line in foreign press. It is said that a group of foreign journalists had visited the area during the autumn to get acquainted with the fortification work, and had asked the name of the chain of fortifications. In those days, there was a lot of talk about the French Maginot-line and the Siegfrid Line protecting the western border of Germany. A young officer, Jorma Gallen-Kallela, the son of Mannerheim’s ex-ADC, who was guiding the visitors had then come up with the name Mannerheim Line. After the outbreak of the Winter War the name appeared in some newspapers whose reporters had been among the visitors.

When the attack of the Soviet army halted at the Mannerheim Line for over two months, highly exaggerated descriptions of the line began to spread in the Soviet Union. It was compared to the Maginot Line, although it contained only four per cent of the amount of concrete device used in the Maginot-line. In practice, the German troops then moved around the Maginot Line in spring 1940. In February 1940, the Soviet troops succeeded in breaking through the Mannerheim Line near Summa by bombing it heavily. After the war the entire line remained in the area ceded to the Soviet Union.