In the 1660s Patriarch Nikon, the head of the Russian Orthodox Church, instituted reforms in Russian Orthodox ritual and usage. These included such things as the wording and number of prayers, the configuration of the hand when making the sign of the cross, the spelling of Jesus' name, and the like. Nikon's stated purpose was to bring the Russian Orthodox Church into closer alignment with the usages of the Greek Orthodox Church of his day, as he believed the Greeks surpassed the Russians in preserving ancient Orthodox tradition.
Whatever the merits of Nikon's position, it was opposed by millions of Russian believers. In the resulting Great Schism Nikon, most of the clergy, the Tsar and many common folk accepted the reforms, resulting in what is today commonly called the Russian Orthodox Church. Other clergy, along with millions of believers, rejected the reforms, sometimes choosing martyrdom rather than abandoning the old ways. For their adherence to the "old ritual" they became known as "Old Believers" or "Old Ritualists", and became subject to fluctuating levels of persecution over the life of the Russian empire and that of the Soviet Union.
Over the course of time, millions of Old Believers fled to the outskirts of the Russian Empire in search of greater religious freedom. Many crossed borders, or stayed put as borders moved around them, and as a result ended up in modern Poland, Ukraine, Romania, Bulgaria, Turkey and China. Some fled the country with the advent of Soviet power. Others stayed. Some groups adopted modern ways in everything but liturgical matters. Others maintained traditional dress, hairstyle, and folkways as part of their Old Believer practice.
Margaret Hixon's 1981 film documents a real-life wedding in the Old Believer settlements of Marion County, Oregon, in the years 1979 and 1980. The film briefly touches on a wealth of traditional arts (embroidery, clothing construction, weaving, vernacular architecture, folk song and foodways) and beautifully presents a whole series of rituals -- the "devichnik" (engagement party), "selling" the bride and her braid, the wedding feast, the bargaining over the dowry, and the ceremony of bestowing gifts and advice on the newlyweds. In English and Russian with subtitles or voice-over translations. (This descriptive material is from the website Old Believers In North America)