After the Russian Civil War, between 41,000 and 44,000 citizens of the former Imperial Russia who opposed the Bolshevik regime emigrated to the Kingdom of Serbs, Croats and Slovenes. Due to difficult circumstances during the civil war and impossible hygienic circumstances upon evacuation from the coasts of the Black Sea, many of them contracted typhoid, smallpox, and tuberculosis. Insufficient number health care institutions in the Kingdom of Serbs, Croats and Slovenes forced Russian humanitarian organizations to establish Russian health care institutions. Consequently, Russian clinics, lazarets, hospitals, dental clinics, sanatoriums, and other health care institutions were operating on the territory of the Kingdom of Serbs, Croats and Slovenes in which mostly Russian doctors worked. It was typical for all Russian health care institutions that they functioned only for a brief period, mostly until the suppression of infectious disease or eviction of most Russian refugees from the place where the institution functioned. One of the few Russian health care institutions which were functioning until the demise of the Kingdom of Yugoslavia was the Sanatorium of the Russian red cross for pulmonary patients in Vurberk. The beginnings of the Sanatorium can be traced back to 1921 when the department of the Russian red cross came to Vurberk and rented castle premises for two years. Sanatorium was then managed by Natalija Aleksandrovna Duhonina. However, the Sanatorium flourished after the arrival of dr. Boleslav Okolo - Kulak in 1923. The doctor facilitated the transportation of the entire inventory of the former Russian sanatorium in Istanbul to Vurberk in 1924. Vurberk Sanatorium thus gained modern medical equipment. In 15 years of operation, 2618 patients were treated there, amongst whom 1817 were Russian emigrants, 780 Yugoslavs, and 21 foreign citizens. The latter included Poles, Romanians, Greeks, Bulgarians, and Italians. The achievements of the Sanatorium for pulmonary patients in Vurberk equalled it with the best European sanatoriums. Unfortunately, it was dissolved after the German occupation in 1941, while the inventory was destroyed when allied forces carried out an air raid on the Vurberk Castle in 1945.