Anglicanism is the most prominent of the Reformation traditions to lay claim to the historic episcopate through apostolic succession in terms comparable to the various Roman Catholic and Orthodox Communions. Anglicans assert unbroken episcopal succession in and through the Church of England back to St. Augustine of Canterbury and to the first century Roman province of Britannia. While some Celtic Christian practices were changed at the Synod of Whitby, the church in the British Isles was under papal authority from earliest times.[4]