Triodion

The Triodion is a liturgical book used in the Eastern Orthodox Church and in some Eastern Catholic Churches that contains the variable texts for the pre-Lent, Lent, and Holy Week services. It governs the liturgical cycle that leads up to Easter, covering the Sundays and weekdays from the Sunday of the Publican and the Pharisee through Holy Saturday. The name Triodion derives from Greek and is traditionally linked to the Lenten hymnography, though the exact origin is a matter of scholarly debate.

Contents and structure include hymns, prayers, readings, and liturgical directives for the entire period from the pre-Lenten weeks through Holy Week. Notable elements include the Great Canon of St. Andrew of Crete, special Lenten troparia and kontakia, and the services of Holy Week. The Triodion is used in conjunction with other liturgical books, such as the Menaion for fixed feasts earlier in the year and the Pentecostarion for Bright Week and the Paschal season.

Usage and scope extend to Orthodox churches worldwide and to some Eastern Catholic Churches that follow the Byzantine Rite. After Holy Saturday, the liturgical cycle advances to the Pentecostarion, which covers Bright Week through Pentecost, while the Triodion ends with Holy Saturday and does not extend into the Paschal season.

History and transmission note that the texts were compiled in the Byzantine period and circulated in Greek and various vernacular traditions, including Church Slavonic and other languages. The Triodion remains a central source for the liturgical practices surrounding Lent and Holy Week in the Byzantine Rite.