The First Book of Common Prayer by Archbishop of Canterbury Thomas Cranmer was first used on the Day of Pentecost in 1549. In The Episcopal Church, we observe this day on a weekday following the Day of Pentecost, as stated in the 1979 Book of Common Prayer calendar at the end of the page for May.
The genius of the Book of Common Prayer is that Cranmer took many of the services that came before and condensed them in an easy-to-worship format. We continue this trend today with our Prayer Books throughout the churches of The Anglican Communion.
Cranmer's goal was also to move the Church of England to Protestantism. While the 1549 Book of Common Prayer made only small changes in that direction, it paved the way for a much more Protestant Prayer Book in 1552, which lives on in the form of the Book of Common Prayer of 1662, still the official Prayer Book of the Church of England. In fact, it is believed if he had survived the reign of Queen Mary I, Cranmer would have continued to make Church of England services even more Protestant in nature, particularly when it came to Holy Communion.
Some may not agree with the direction Cranmer took anglican liturgy, while others might wish he had gone further than he did. In The Episcopal Church, we have never been in quite the direction of Cranmer's final Prayer Book, basing our first Book of Common Prayer on The Scottish Episcopal Church instead of the 1662 Book of Common Prayer. Yet without Cranmer, we would have no Prayer Book at all. We continue to make services available for all worshipers to follow while expressing our theological understanding of our relationship with Christ Jesus, whether similar or different from Archbishop Cranmer's views.