Russian Historian Vasiliev's "History of the Byzantine Empire, 324-1453" is one of the best history books in the historiography of Byzantine! Vasiliev questions the Byzantine society during the history, searchs the documents of Byzantine state's in detail, tries to describe the different stages of Byzantine political, legal, social history. Vasiliev's approach to the Byzantine state explains the "complexity" of Byzantine history in his historiography. After the "collapse" of Roman state, in Constantinople (Istanbul), the Byzantine state (Eastern Roman) was founded, structured, developed by the Byzantine ruling classes - the Byzantine state was based on "the slavery" mostly, then the Byzantine "feudality" was structured, so, the Byzantine state was "a class society" during the history. Vasiliev's "History of the Byzantine Empire, 324-1453" is the historical description of Byzantine which uses the modern historiographical rules, methodology and the ways of comprehensing.