Questions concerning sacred spaces and their relationship to ritual is of interest to historians of religion and others as well. How sacred spaces emerge and are constructed and what relationship they have to rituals are some of the areas that are dealt with in this study in relation to Syriac Orthodox liturgy. The purpose of this study is to create a better understanding of how the Sedr¿ of Entrance has been practiced in earlier periods and architectural contexts and to investigate what role the entrance rite may have had in constructing the sanctuary as sacred space and the worshipping community as church. The Sedr¿ of Entrance is a prayer employed during the rite of entrance into the altar in Syriac Orthodox Eucharistic liturgy. This study uses ritual theory to frame the rite of entrance and studies the intersection of ritual text, action and place. Two research questions are addressed: a) How is the rite of entrance into the altar, in the Syriac Orthodox liturgy, performed during the 9th-13th centuries? b) How does the rite of entrance construct the sanctuary as sacred space and the worshipping community as church? The study builds on historical material, manuscripts from the 9th to the 13th centuries, architecture, and other historical textual material. The rite of entrance is framed with ritual theory. Theological analysis is also used to support the ritual theory. The themes of the dissertation include, among others, the relationship between ritual process, ritual place, and the ritual body. It also explores the role of language in the ritual process.