The Book of Common Prayer emerged from the experience of the late medieval church in England. The form of Christian worship at that time followed the Roman Rite, with substantial variation from parish to parish, and was conducted entirely in Latin. As Reformation thought swept across England in the 16th century and the church broke away from Rome, Thomas Cramner, the Archbishop of Canterbury, took up the task of creating a new liturgy for the breakaway Church of England.
The first Book of Common Prayer, published in 1549, created a uniform pattern of worship across all parishes in the new Church. It was also written in English rather than Latin, and consolidated the liturgies of seven different worship manuals (the Missal, the Breviary, the Manual, the Pontifical, and three different books of chants and plainsong) into one book. The word "Common" in the title is not intended to suggest it is ordinary or mundane, but rather universally accessible to all worshippers.
Numerous revisions to the BCP have taken place over the centuries as our expressions of worship have gradually changed, but much of the structure and spirit of the earliest versions still remains. Today, the 1979 Book of Common Prayer is the version authorized for use in all congregations of the Episcopal Church. From California to New Caledonia, from Pakistan to Peru, Anglicans and Episcopalians across the world are united in heart and voice every Sunday through this beautiful instrument of worship.
The entire 1979 Book of Common Prayer in English can be found online here.