Griffin’s first monograph, The Liturgical Past in Byzantium and Early Rus, was published by Cambridge University Press in 2019. The chroniclers of medieval Rus were monks, who celebrated the divine services of the Byzantine church throughout every day. His study is the first to analyze how these rituals shaped their writing of the Rus Primary Chronicle, the first written history of the East Slavs.

The Liturgical Past has been awarded two international book prizes. In 2020, it was awarded the W. Bruce Lincoln Book Prize from ASEEES. The prize recognizes ‘a first published monograph that is of exceptional merit and lasting significance for the understanding of Russia’s past’. The book was also the winner of the Ecclesiastical History Society Book Prize for the best first book published in 2019.