This book presents the dramatic and convoluted story of Armenia's ecclesiastical relations with Byzantine and subsequently Roman Christendom in the Middle Ages. It is built up on a broad foundation of sources - Armenian, Greek, Latin, and Syrian chronicles and documents, especially the abundant correspondence between the Holy See and the Armenian Church, which has been published by the Pontifical Commission for the Redaction of the Code of Oriental Canon Law (Pontificia Commissio ad redigendum Codicem iuris canonici orientalis). Krzysztof Stopka examines problems straggling the disciplines of history and theology and pertinent to a signal, though not widely enough known episode in the story of the struggle for Christian unity.