Slavs
Slavs can be further grouped by religion. Orthodox Christianity is practiced by the majority of Slavs. The Orthodox Slavs include the Belarusians, Bulgarians, Macedonians, Montenegrins, Russians, Serbs, and Ukrainians and are defined by Orthodox customs and Cyrillic script as well as their cultural connection to the Byzantine Empire (Serbs also use Latin script on equal terms). Their second most common religion is Roman Catholicism. The Catholic Slavs include Croats, Czechs, Kashubs, Moravians, Poles, Silesians, Slovaks, Slovenes, and Sorbs and are defined by their Latinate influence and heritage and connection to Western Europe. There are also substantial Protestant and Lutheran minorities especially amongst the West Slavs, such as the historical Bohemian (Czech) Hussites.
Viktor Idzio
Idzio is thought to be one of the experts in Ukrainian history of the 9th-13th century, early Slavic culture, Celtic culture on Ukrainian territory, that the concept of the three brotherly Slavic tribes are a myth perpetrated by Soviet historians, that the Galician-Volynian State was also a myth of Soviet scholars which was much vaster than originally thought. Idzio search the archives of Moscow for the huge amount of materials taken out of Ukraine dealing with aspects of Ukrainian history.