This study proceeds historically, from the origins of the Eucharist up to our own day. Unlike most studies of this kind, it includes an introduction to and developmental summary of the diverse Eucharistic liturgies of the Christian East. It also explores the various Western rites (Ambrosian, Gallican, and Mozarabic) in addition to the Roman. With regard to theological themes, the authors give special attention to the topics of real presence (including the consecration of the bread and wine) and eucharistic sacrifice, the most central and most ecumenically challenging issues since the...