The origin of the tonsure remains unclear but it certainly was not widely known in antiquity. There were three forms of tonsure known in the 7th and 8th centuries: * The Oriental, which claimed the authority of St. Paul the Apostle (Acts 18:18) and consisted of shaving the whole head. This was observed by churches owing allegiance to Eastern Orthodoxy. Hence Theodore of Tarsus, who had acquired his learning in Byzantine Asia Minor and bore this tonsure, had to allow his hair to grow for four months before he could be tonsured after the Roman fashion, and then ordained Archbishop of Canterbury by Pope Vitalian in 668. * The Celtic, which consisted of shaving the whole front of the head from ear to ear, the hair being allowed to hang down behind. This is a style that was inherited fro