DIACONICON (Διακοινωνόν), DIACONICO. — ART.
Small chamber, often apsidal, found in basilican churches beside the apse, on the side opposite the *prothesis*.
The use seems to derive from the East, particularly Syria, where so many elements of Christian basilicas were developed, and where it already appears in pagan buildings; it is frequent in Ravenna’s churches, rarer in the Roman region, where it is found only in S. Maria Antiqua, in S. Sinfonosa, and in the basilica of Pammachio at Porto. It also served as a treasury for preserving sacred vessels and relics.
LITURGY
The term is used in several senses. It means: 1° the liturgical book of the Byzantine rite containing the litanies and supplications, and the prayers recited by the deacon in the various church offices (L. Allatius, *De libris et rebus ecclesiasticis Graecorum*, diss. I, Paris 1646, p. 97); 2° the supplications themselves, which, besides the names of *ektēnes eirēnaīs*, are also called *diakonaí*. E.g.: τὰ διακοινὰ τῶν φωτισμένων (supplications for the catechumens during Lent [Euchologion, Rome 1873, p. 121]); 3° the place where the deacons stand. This place is before the main door of the sanctuary, where the deacon recites the supplications in the name of the people: “Ἀρχεται ὁ διακοινός ἐν τῷ διακοινῷ ἐν εἰρήνῃ” (J. Morinus, *De sacris Ordinationibus*, Paris 1655, p. 104). Above all, however, it is the place where the deacons once prepared the bread and wine destined for the Sacrifice. Situated to the right of the sanctuary, it was later used to store vestments and sacred vessels, liturgical books, etc. It is like the sacristy of the Eastern churches (J. Goar, *Εὐχολόγιον, sive Rituale Graeco-rum*, Venice 1730, p. 13). Placido de Meester