Antique Russian Icon
The Benedictines (530 AD) were the only religious order(1) existing prior to division of the church into Eastern and Western parts in 1054(2). The Franciscans (1209 AD), Dominicans (1216 AD), the Augustinians (1244) and Jesuits (1540 AD) were founded after the Church divided between East and West.(3)
The significance of the antiquity of the Benedictine order is that prior to the division of the Church in 1054 there were Benedictine monasteries in Russia which retained their Benedictine traditions after the division. They may have rejected the Western Church and its pope, but they saw no reason to depart from the Benedictine way. Even today there are Orthodox Benedictine monasteries. One is in Canada. It is the Monastery of Christ the Saviour in Hamilton, Ontario, Canada.
Picture is IMG_1891, Antique Russian Icon for sale at Izmaylovo Market, by beggs and is used subject to license.
(1) The term Benedictine Order is described as follows in the New Advent Encyclopedia:
"The term Order as here applied to the spiritual family of St. Benedict is used in a sense differing somewhat from that in which it is applied to other religious orders. In its ordinary meaning the term implies one complete religious family, made up of a number of monasteries, all of which are subject to a common superior or "general" who usually resides either in Rome or in the mother-house of the order, if there be one. It may be divided into various provinces, according to the countries over which it is spread, each provincial head being immediately subject to the general, just as the superior of each house is subject to his own provincial. This system of centralized authority has never entered into the organization of the Benedictine Order. There is no general or common superior over the whole order other than the pope himself, and the order consists, so to speak, of what are practically a number of orders, called "congregations", each of which is autonomous; all are united, not under the obedience to one general superior, but only by the spiritual bond of allegiance to the same Rule, which may be modified according to the circumstances of each particular house or congregation. It is in this latter sense that the term Order is applied in this article to all monasteries professing to observe St. Benedict's Rule."
(2) The Great Schism: The Estrangement of Eastern and Western Christendom is an article describing the division from the Orthodox aspect. From the Orthodox Christian Information Center website.
(3) The Western church is generally called Catholic and the Eastern church is composed of several churches, the largest being the Orthodox, but the Eastern part of Christianity also includes, for example the Coptic Church. See the several Eastern churches described and listed.
However, there are many Catholic churches in the same areas in the East where the "Eastern" churches are the primary form of Christianity. These are real Catholic -- in communion with the Pope. These churches are called Eastern Catholic churches. See list of Eastern Catholic rites and churches.