ウクライナ人民共和国軍
In February 1919, he was mobilised as an army physician by the Ukrainian People's Army and assigned to the Northern Caucasus. There, he became seriously ill with typhus and barely survived. In the Caucasus, he started working as a journalist, but when he and others were invited to return as doctors by the French and German governments, Bulgakov was refused permission to leave Russia because of the typhus. That was when he last saw his family; after the Civil War and the rise of the Soviets most of his relatives emigrated to Paris.