John L. Fennell 
A History of the Russian Church to 1488 [PDF ebook] 

The Russian church is central to an understanding of early Russian and Slav history, but for many years there has been no accessible, up-to-date introduction to the subject in English – until now. The late John Fennell”s last book, is a masterly survey of the development, nature and role of the early Church in Russia from Christianization of the country in 988, through Kievan and Tatar poeriods to 1448 when the Russian Church finally became totally independent of its mother-church in Byzantium.