Michel Kaplan examines how sacredness is expressed through architecture and visual culture in both Byzantine and Western contexts. Drawing on a wide range of medieval sources, the study explores the interplay between liturgical function, symbolic inscription, and spatial design in churches, monasteries, and other holy sites. By comparing Byzantine architectural principles with Western medieval practices, Kaplan highlights both shared theological concepts and distinctive regional expressions of the sacred. The book situates these artistic and architectural choices within broader cultural and transcultural exchanges, offering insight into how sacred space was negotiated, perceived, and materialized across centuries. Richly illustrated and grounded in rigorous scholarship, the work provides a valuable resource for readers interested in medieval art, religious studies, and the history of architecture.