 This argument is linked especially with the branch theory upheld by many Anglicans, (i.e., that the church in communion with the Pope is only one branch of a divided Catholic Church, of which the Eastern Orthodox Church and Anglicanism are the other two principal branches).In 1864, the Holy Office rejected the branch theory, affirming in a letter written to the English bishops that the Roman Church is not just a part of the Catholic Church and stating that "there is no other Catholic Church except that which is built on the one man, Peter.