Anglicanism is a tradition within Christianity comprising the Church of England and churches which are historically tied to it or hold similar beliefs, worship practices and church structures. The word Anglican originates in ecclesia anglicana, a medieval Latin phrase dating to the Magna Carta (1215) and before, which means the "English Church".
Adherents of Anglicanism are called "Anglicans". There is no single Anglican Church with universal juridical authority, since each national or regional church has full autonomy, but the great majority of Anglicans are members of churches which are part of the international Anglican Communion, which is the third largest Christian communion in the world, after the Roman Catholic Church and the Eastern Orthodox Church. As the name suggests, the churches of the Anglican Communion are linked by affection and common loyalty. They are in full communion with the See of Canterbury and thus the Archbishop of Canterbury, in his person, is a unique focus of Anglican unity. He calls the once-a-decade Lambeth Conference, chairs the meeting of primates, and is President of the Anglican Consultative Council. There are, however, a number of churches that are not within the Anglican Communion which also consider themselves to be Anglican, most notably those referred to as continuing Anglican churches, and those which are part of the Anglican realignment movement.
Anglicans base their Christian faith on the Bible, traditions of the apostolic Church, apostolic succession ("historic episcopate"), and writings of the Church Fathers. Anglicanism forms one of the branches of Western Christianity; having definitively declared its independence from the Holy See at the time of the Elizabethan Religious Settlement. Many of the new Anglican formularies of the mid-16th century corresponded closely to those of contemporary Protestantism. These reforms in the Church of England were understood by one of those most responsible for them, the then Archbishop of Canterbury, Thomas Cranmer, as navigating a middle way between two of the emerging Protestant traditions, namely Lutheranism and Calvinism. By the end of the century, the retention in Anglicanism of many traditional liturgical forms and of the episcopate was already seen as unacceptable by those promoting the most developed Protestant principles.