Unlike many other religious ceremonies, there are no traditional vows or oaths exchanged in the Orthodox Christian sacrament of marriage. The celebration instead consists of two parts: a ring exchange, or Betrothal, and a crowning of the couple with metal or floral crowns (which explains the origin of the flower crown!). Specific ethnic Orthodox congregations, such as Russian Orthodox or Greek Orthodox, all share the identical faith and wedding rituals but even though their ethnic customs may vary, these are not considered part of the Church tradition.
Source: Father John Matusiak, Orthodox Church in America
See More: Wedding Ceremony + Wedding Vow Ideas