THE TONSURE CONTROVERSY:

The Roman tonsure was formed by shaving the top of the head in a circle leaving a crown of hair around it. The Eastern tonsure, sometimes called the Pauline tonsure, was total. The Celtic tonsure was formed by shaving all the hair in front of a line drawn from ear to ear.[125] In the controversy of the seventh century the Roman party traced their form to St. Peter and attributed that of their opponents to Simon Magus.[126] The Irish form, ab aure ad aurem, existed in St. Patrick’s time[127] and was probably druidical in origin.[128]

These two questions, though in themselves of minor importance, gave rise to a controversy of many years’ duration. Eventually the Roman practice was adopted by the whole Celtic Church, but not without a struggle, some localities clinging tenaciously to the traditional usage long after the general acceptance of the Continental practice. The Southern Irish were the first to conform. Having received an admonition from Pope Honorius they convened a Synod about 630 A.D. and as a result of their deliberations decided to adopt the Roman usage. The North of Ireland held out much longer, being influenced by Iona and its dependent monasteries in Ireland.[129] The dates at which the different parts of the Celtic Church conformed with the Roman practice in regard to the celebration of Easter are given below.[130] Possibly the coronal form of tonsure was adopted at the same time.

YEAR.—DISTRICT AFFECTED BY THE CHANGE:[130]

630 A.D.South of Ireland.
664Northumbria converted by Irish
 missionaries from Iona.
692North of Ireland.
705East Devon and Somerset,
 the Celts under Wessex.
710The Picts of Scotland.
716–718Iona.
721Strathclyde, the South-west of Scotland.
768North Wales.
777South Wales.
909Parts of Cornwall.