The term ritus (ceremony) underwent a very difficult development in canon law history. Because of misunderstandings about the content of the term, which consist not only of the liturgically different ceremony but also of an entire set of theological, spiritual and disciplinary tradition, there were past tensions between the Roman and Eastern churches.
Today, Eastern churches include not only several dozen Orthodox churches that have gradually emerged since 1054, when the large Eastern schism took place, but also the Assyrian church, which had already split from Rome by 410, and also the ancient (pre-Chalcedon) churches, which did not accept the conclusions of the Council of Chalcedon of 4521. Because of its tradition and the ceremony arising from that tradition, the Roman (Latin) church is connected to the Eastern Catholic churches, which are currently endangered by growing violence and aggression, particularly in the Middle East.