The Polychronion (Greek: Πολυχρόνιον, "many years"; Georgian: მრავალჟამიერი, Georgian: mravaljamieri; Church Slavic; Old Slavonic; Church Slavonic; Old Bulgarian; Old Church Slavonic: многая лета|translit=mnogaya leta) is a solemn encomium chanted in the liturgy of the Eastern Orthodox and Byzantine Catholic churches. In the Roman rite, it is the equivalent of the liturgical acclamation Ad multos annos.
The Polychronion is chanted for the secular authorities (Orthodox monarchs are mentioned by name, non-orthodox leaders are mentioned by title), the church authorities (the Patriarch or diocesan bishop), individuals on specific occasions, and the whole community of Orthodox Christians.
There are two forms of the Polychronion in the Slavic usage:
The Polychronion as chanted for a sovereign is derived from the traditional Latin acclamation "Ad multos annos" accorded by the populace to Roman Emperors. The acclamation was continued in Byzantine times in partially hellenized form: "Immultos annos", before it was completely translated into the Greek form "Εἰς πολλὰ ἔτη":
Πολυχρόνιον ποιῆσαι, Κύριος ὁ Θεός
τὸν εὐσεβέστατον Βασιλέα ἡμῶν [regnal name].
Κύριε, φύλαττε αὐτὸν
εἰς πολλὰ ἔτη. (three times)
Polychronion poiēsai Kyrios o Theos
ton eusebestaton basilea ēmōn [regnal name].
Kyrie phylatte auton
eis polla etē. (three times)
Grant long life, O Lord God,
to our most pious king [regnal name].
O Lord, preserve him,
unto many years. (three times)
Depending on circumstance, the names of other members of the reigning family can be added between the second and third lines, in the same form ("and to our most pious Queen X", "and to their most pious heir the Crown Prince Y" etc.). Since there remain no Orthodox monarchies nowadays, the Polychronion is only chanted for ecclesiastical authorities, namely the Patriarch or diocesan bishop, in which case it is usually called the "Phēmē" (Φήμη; "Fame").