DIPTYCH, a tablet consisting of two leaves, light boards, held together by a hinge. In the time of the Roman empire dip tychs were much used in correspondence be tween friends and were given by magistrates inscribed with names and portraits to friends on the assumption of office. Even when three boards or more were used the name diptych (Sintoxos, folded double) was generally re tained instead of triptych, tesseraptych, etc. Diptychs figure largely in the history of the Church for several centuries, being tokens of intercommunion between the assemblies of the faithful throughout the world. The use of dip tychs in the liturgical service was in full vogue in the middle of the 4th century and it must have commenced much earlier. It was con tinued in the Latin Church to the 12th century and in the Greek Church to the 15th. The Diptychs of the Living had inscribed on them the names of the pope, patriarchs, bishops then living and presiding over the faithful in their respective spheres; also the names of the clergy of the particular churches in which they were kept ; names also of benefactors of the churches, of the emperor and the empress, etc. For all
these the faithful offered their prayers. The Diptychs of the Dead contained usually the names which had once been written in the Diptychs of the Living. In the diptychs were also inscribed the names of the Virgin Mary, martyrs and other saints. If any name, whether of the living or the dead, was erased from the diptychs it signified that the person was re garded as out of the communion of the Church. The diptychs both of the living and dead were read from the umbo or pulpit to the congrega tion. Church calendars and martyrologies seem to have had their origin in the diptychs. In the Roman Missal, the marks of the diptychs are very evident. At the prayer, "Te igitur," the names of the reigning pope and the bishop of the diocese are mentioned. In other prayers of the Mass the diptychs are followed. Con sult Kraus, Benedict XLV, 'De Missa.'