The monograph is the first to comprehensively examine K. G. E. Mannerheim’s relations with Russia, starting from the period of the revolution and civil war in Finland in 1918 until the end of World War II. The author pays special attention to controversial issues and the “many faces” of the Finnish marshal as the ability, changing tactics, to consistently implement the main task - the fight against a strong Russia/USSR in alliance with the Kaiser and later Nazi Germany.

Mannerheim’s plans for the creation of “great Finland” at the expense of the USSR, his absence as the main accused at the Helsinki trial of the main culprits of Finland’s involvement in the Second World War on the side of Nazi Germany is explained.

The work was carried out on the basis of a rich corpus of little-known Russian and Finnish archival sources, scientific research and memoirs.