The author at the centre of this study, Russian priest-theologian Nikolai Nikolaevich Afanas'ev, was perhaps the most influential thinker about the Church Russia has produced. In Aidan Nichols's careful evaluation, he emerges as a key figure in the rapprochement of Christian East and West, and most notably of the Orthodox and Catholic churches. Nichols illustrates how Afanas'ev has been influential in two key respects: first of all in his conviction that the Eucharist constitutes the foundation of the whole Church; and secondly in his contribution to an Orthodox understanding of the role of the Roman Church and bishop in the context of a united Church. Afanas'ev's achievements are seen to have continuing relevance in view of the inauguration of the Orthodox-Catholic dialogue at the monastery of St John on Patmos in 1980, and the importance of his thinking in terms of contemporary ecumenism becomes clear. It is to such a reappraisal that this book - concerned as it is with how Russian orthodoxy understands the Church - is devoted, in the hope of an eventual restoration of unity between the Orthodox of all the Russias and the see of Rome.