The Byzantine Rite is the liturgy of a city before it is the liturgy of an empire. Constantinople inherited the liturgical family of Antioch, and from the fourth century onward reworked it under the pressures of an imperial capital: processions through the streets, a cathedral of unprecedented scale in Hagia Sophia, and a court whose ceremonial and whose theology both flowed into worship. The rite that resulted is built on a few great structures.
The Divine Liturgy, in the redactions bearing the names of John Chrysostom and Basil, is its eucharist. Around it runs the daily cycle of services, vespers, compline, midnight office, matins and the hours, and around the week runs the octoechos, the cycle of eight tones that rotates the church's hymnography. The year interlocks two calendars, the fixed feasts and the movable paschal cycle, and the whole is regulated by the Typikon, the book of rubrics that tells the singer and celebrant how the overlapping cycles combine on any given day.
Historians of the rite describe a long synthesis: the cathedral usage of the Great Church, with its sung offices, gradually merged with the monastic usages of Palestine and of the Studios monastery in the capital, so that what the Orthodox world now celebrates is a monastic-cathedral hybrid completed in the late Byzantine centuries and spread wherever the church of Constantinople had daughters.