Arvi Kalsta

Kalsta's parents were master builder Bror Gustaf Adolf Grönberg and Ida Sofia Skutnabb.

Kalsta married Elin Impi Tika in 1920, whom he divorced in 1937; he remarried in 1939 to Kerttu Annikki Savolainen.

Grönberg took part in the battles of the First World War on the eastern front of Germany on the Misse River and the Gulf of Riga, from where he was sent for special missions to northern Sweden and Finland from 4 December 1916 to 14 October 1917.

[2][3] Kalsta's military career at the time was cut short after he shot an armed Polish prisoner of war who'd received special permission to carry a weapon by Carl Gustaf Emil Mannerheim.

[5] Kalsta was part of the Lapua movement's group, which kidnapped the Social Democrat Deputy Speaker of Parliament and the Mayor of Tampere, Väinö Hakkila, from 17 to 18 July 1930.

Kalsta was convicted and served time in prison for kidnapping, albeit his accomplices were all released on probation.

[6][7] On 10 September 1932 Kalsta traveled to Germany with Thorvald Oljemark to get acquainted with the activities of the East Prussian District Staff of the German National Socialist Workers' Party (NSDAP).