conradi was born in saint petersburg to a family of swiss businessmen, owners of a chocolate factory established in 1853 by conradi's grandfather. upon the outbreak of world war i he joined the russian imperial army with the personal permission of nicholas ii and fought on the eastern front. during the bolshevik revolution most of his family was killed: his father was executed in saint petersburg on 26 november 1919, his brother victor taken hostage and executed in 1918, and two further siblings disappeared during the red terror. after the unsuccessful campaign of the wrangel army he moved to switzerland, radicalized against the bolshevik government and planning revenge.