The Byzantine Rite travelled by mission and by translation. The ninth-century work associated with Cyril and Methodius and their disciples carried it into the Slavic lands in a new liturgical language, Church Slavonic, and the conversion of Rus in 988 made that translation the worship of the largest Orthodox nation. The rite thus became the shared possession of churches that are administratively independent of one another: the Greek-speaking patriarchates, the Slavic churches, the Romanian, Georgian, Arabic-speaking and missionary churches, each celebrating the same services in its own tongue and with its own musical tradition, from Byzantine chant to Slavic polyphony. It is also the rite of the Eastern Catholic churches of Byzantine heritage, communities in communion with Rome that keep the Orthodox liturgical books, a situation that has made the rite a crossing point of church politics for four centuries.
For all its variety of language and music, the rite's furniture is everywhere recognisable: the iconostasis screening the sanctuary, the antidoron and the leavened bread, censing at the appointed moments, and a liturgical ethos that treats the service as an entry into heavenly worship rather than an instruction hour. Its calendar begins the church year on the first of September, and its paschal reckoning still follows the Julian calculation in most of the Orthodox world, which is why Orthodox Easter usually falls after the Western feast.