(the following continues to be edited & updated as needed)
What is the Western Rite Orthodox?
The Holy Catholic Church; otherwise known as the Orthodox Church, was united across all of the Holy Roman Empire. From Byzantium in the east all the way to Rome in the west and even in the British Isles and what is now modern-day France. The Church existed in a way that was united in doctrine and theology for over a thousand years after the day of Pentecost in AD 33.
The Liturgy, or “work of the people” varied from east to west due to the cultural and societal makeup of the regions in which the Church existed. In the West, the Liturgy, like the Latin language, tended to be terse and Patristic. Yet slight differences were reflected in the Liturgies of Rome, Milan, Toledo, and Lyons. The differences came to be known as rites: Ambrosian, Roman, Mozarabic, and Gallican and were named after Saints Ambrose, Gregory, and Germanus. Further, within the Roman Rite there developed “Uses” of which the post-schism Sarum is perhaps best known.
The Christians of the Eastern Roman Empire (*Byzantium or Constantinople) primarily celebrated the Liturgy of St. John Chrysostom and the Liturgy of St. Basil the Great which, reflecting the Eastern culture continued to evolve. Each of these Liturgies contained the essential elements that were required to be canonically correct and united in theology, but differed in appearance, hymnody, and language. Much was borrowed between them in the early years less in the latter.
In AD 1054*, what has become known as the Great Schism occurred, thus ending effective communication and cooperation between the Church in the east and the west. The Church in the west began to operate as its own distinct entity that was separate from the Christian Church in the east. It became known to the world as the Latin Church whereas the church in the east became known as the Eastern Orthodox Church.
It is noteworthy to remember that the Western Rites were almost a thousand years old when Christianity was introduced to the people of Kievan Rus, modern day Russia.
The Western-Rite of the Orthodox Church is a concerted effort by the Russian Orthodox Church Outside Russia among others to pastorally respond to the numerous requests of Western Christians to re-establish the Western Church as it existed prior to the Great Schism. It is an outreach to peoples who have grown up in countries that have been populated by Protestant and Roman Catholic communities to offer the fullness of the Faith as it existed prior to the schism. Many people in America and other countries who would not normally come into the Orthodox Church due to the uniqueness of the worship style of the Eastern liturgies, or the ethnic cultures, may find something comfortably familiar in the Western-Rite liturgies, while retaining the unity in sound doctrine and theology of the Orthodox Church.
Source: ROCOR WR Community Website
*Now we must say that in reality the Great Schism between East and West did not take effect everywhere at once like extinguishing a candle. There were regions of Western Europe that remained Orthodox. I believe it can be safe to say that the Great Schism entered its full beginning as with the blossoming of the modern Roman Catholic Church with the enthronement of the reformer Pope Gregory VII in 1072 A.D. Aside from being logical, there is a certain utility in this thought. It allows us access to more saints and more liturgical materials.
UKASE of the MOSCOW PATRIARCHATE TO THE MOST REVEREND BENJAMIN, ARCHBISHOP OF THE ALEUTIAN ISLANDS AND NORTH AMERICA regarding Bishop Winnaert, who heads the Catholic Evangelical Church, “with a request to undertake the necessary steps toward uniting his community with the Orthodox Church and to solicit the Moscow Patriarchate for a conclusion on his request.
Item № IX. of this 1936 Ukase states: “The united parishes, using the Western Rite, shall bear the name ‘Western Orthodox’.” We at St John Hermitage consider the nomenclature, “Western Rite Orthodox” is a diminutive and triviality of what is truly Western Orthodoxy equal to Eastern Orthodoxy.
A Synopsis of Western Orthodox History