Diptych

Diptych, a two-leaved writing tablet, in which were inscribed the names of living or dead Christians to be read aloud during the celebration of the eucharist. The practice was due originally to a custom under the Roman empire of magistrates, such as consuls, prætors, and ædiles, at the commencement of their office, giving away tablets inscribed with their names and portraits. In Christian usage it was in very early times customary to inscribe the names of dead bishops—a beginning of the calendars and martyrologies of later days. The insertion of the names of living persons may have had its origin in the ancient recital of the names of those who had voluntarily furnished the elements for the holy communion. It afterwards was extended to include the names of the living faithful, especially those in authority, ecclesiastical and civil. The commemoration of the faithful dead was originally distinct from any special prayer on their behalf. The earliest diptychs in existence are not older than the 5th century of our era. They are of various sizes, rarely exceeding eight inches by four, are sometimes of ivory and metal, as well as wood, and are adorned with an art that is elaborate, if not always beautiful.