This is a collection of seventeen selected papers from the Third International Congress of the Society of Oriental Liturgy, held in Volos, Greece, in 2010. The Society is a non-confessional association of scholars dealing with the liturgical traditions (and related disciplines) of the Eastern Christian Churches. These papers reflect studies on the Ethiopian, Georgian, Hagiopolite, Greek, Bulgarian, Slavonic, early Patristic, East Syriac, and West Syriac liturgies across a wide range of countries and cultures. Among other topics, the authors study the texts of liturgical services (including the critical question of translations), archaeology, liturgical music, iconography, mystagogical commentary, and liturgical theology. The papers deal with both the historical practice of the Churches and their present-day usages. The authors examine not only what has been the liturgical usage of the Eastern Churches in their countries of origin, but also how these liturgies are adapted and celebrated in the diaspora.