Term applied not to one uniform rite, but to a variety of rites used in the ancient churches of Great Britain and Ireland, also in some monasteries founded by Saint Columbanus and his disciples in France, Germany, Switzerland, and Italy. Little certain knowledge is to be had about them. They were in use from the earliest times until about the 13th century, and differed from other rites in determining the date of Easter, the form of tonsure, and the manner of administering Baptism. They were composed of original, Gallic, and Roman elements.