The shaving of the hair at the top of the head of a priest or monk, by which he is distinguished from a layman. Traditionally the shaven area is said to represent the crown of thorns and to have been instituted by the apostles Paul and Peter. Probably the custom entered Christianity through the ascetics of the fourth and fifth centuries who perhaps adopted the custom from heathenisme.g., the priest of Isis. In contemporary Roman Catholic practice the rite of entrance to the clerical life involves the cutting of five pieces of the candidate's hair, with full tonsure later (except in the USA, England, and some other countries); the tonsure, however, is much smaller than the earlier Roman or coronal tonsure which left only a fringe of hair around the head. Originally the Orthodox Church required the shaving of the whole head, but now it is usual for the hair to be cut short instead. The early British (Celtic) Church required a tonsure for which the hair was cut at the front and at the sides, leaving one half of the head with hair.