In 1913 Bulgakov married Tatiana Lappa. When the First World War started he volunteered with the Red Cross as a doctor. Bulgakov was sent to an area where fighting was heavy, and he was badly injured at least twice. In 1916, he graduated from the Medical School of Kiev University. Bulgakov then joined the White Army with his brothers. They fought against the communists who were taking control of Russia. Bulgakov also fought in the Ukrainian People's Army.