The Russian historian I.P. Filevich (1856–1913) was a native of Chełm Land and the son of a Uniate priest, a native of Galicia, who had been invited to Kholmshchyna by the Russian authorities. I.P. Filevich devoted his life to studying the history and modern state of Carpathian Rus, including his native Russian Zabuzhie, which, according to the historian, played an important role in Russian history, but was ignored by Russian historiography, since the few works by Russian researchers, mostly done during their visits to these regions, could not fill this gap. Polish historians were biased in their coverage of the history of these terrotiries, considering them originally Polish. There are few works by Galician-Russian historians D.I. Zubritsky, A.S. Petrushevich, I.I. Sharanevich and others, but they were almost unknown in Russia and failed to give a complete picture of the history of Carpathian Rus either. In his works, I.P. Filevich raises the issues of the history of Galicia and Chełm Land. In his Master’s thesis "The Struggle of Poland and Lithuania-Rus for the Galician-Vladimir Legacy", he explored the "dark" period in the history of Galician Rus – from 1340 to 1433, before the occupied lands were finally annexed to Poland to form the Ruthenian Voivodeship. In his doctoral dissertation "History of Ancient Rus. Vol. 1. Territory and Population", he described the history of the study of Carpathian Rus in modern times and tries to identify the western boundaries of the "Russian territory", indicating the presence of the Russian population in Transylvania. In other works, he characterized the reunification of the Uniates and the "return to the Russian roots" in Chełm Land, analysing the mistakes made during this process. I.P. Filevich studied the history of Austrian rule in Galicia, the social and political life of the Rusins, the history of the union in Galicia and Chełm Land, the fate of the Galicia-Vladimir land within Poland, and the history of the struggle between Catholicism and Orthodoxy. He also emphasised the importance of studying the "geographical nomenclature". His works aroused general, scholarly and political interest in the problems of Carpathian Rus, including Chełm Land, and ultimately contributed a lot to the solution of the problem of separating Chełm Land and Podlasie into a separate province.