This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Byzantine Liturgical History studies how the worship of the Eastern Christian tradition, its texts, its chant and its calendar, took the shape it holds today within Orthodox practice. Its method is historical and textual, tracing, through manuscript and documentary evidence, when a specific rite, feast or liturgical text first entered use and how its form changed as it was copied, translated and revised across the centuries of Byzantine and post Byzantine practice. A question the field can answer that a reading of a modern service book cannot is when a given hymn or feast day actually entered the calendar, and whether the version now in use matches an earlier manuscript witness or represents a later revision.
The discipline sits within Liturgiology, the broader study of how Christian worship developed across traditions, and belongs among the humanities rather than the natural or social sciences, since its evidence is textual and documentary rather than experimental. Its subject is the whole of Eastern Christian worship as the Byzantine tradition shaped it, the eucharistic liturgy, the daily office, the hymnography of the church calendar and the music that carries it, studied as a historical development rather than a fixed inheritance.
As a named field of scholarship it dates to around 1910, when its historical and textual methods were established as a distinct scholarly pursuit rather than an incidental part of general church history. Since then, it has been the discipline able to say, for a specific feast or a specific chant, not only that Orthodox practice holds it today but when that practice began and how it has moved.