The Book of Common Prayer is the foundational liturgical book of the Anglican tradition, and its use, the ordering of worship, daily prayer and the sacraments according to its set forms, has shaped English-speaking Christianity for nearly five centuries. First produced in 1549, largely through the work of Archbishop Thomas Cranmer during the English Reformation, it gathered the services of the church into a single vernacular volume so that clergy and people might pray together in a "common" prayer that all could understand and share, replacing the many and varied Latin books of the medieval church. Its daily offices of Morning and Evening Prayer, its order for Holy Communion, and its rites for baptism, marriage, and burial gave the Church of England a unified pattern of worship, and its cadenced English prose has had an influence on the language rivalling that of the King James Bible.
Revised through successive editions, notably in 1552, 1559 and the enduring version of 1662, and adapted by the Anglican churches of many nations into their own prayer books, it remains a defining mark of Anglican identity. The tradition holds that its fixed forms embody and safeguard the church's belief, on the principle that the law of prayer is the law of belief: what the church prays shapes and expresses what it holds. Its regular, repeated use trains worshippers over a lifetime in the words of scripture and the rhythms of the Christian year, and disputes over its wording and its imposition have at times been fierce, reflecting the weight the tradition places on common, ordered prayer as the bond of its unity and the vehicle of its faith.