O.E.
beard "beard," from W.Gmc.
*barthaz (cf. M.Du.
baert, Ger.
bart), seemingly from PIE
*bhar-dha "beard" (cf. O.C.S.
brada, Lith.
barzda, and perhaps L.
barba "beard"). The verb is from M.E. phrase
rennen in berd "oppose openly," on the same notion as modern slang
get in (someone's) face. Pubic hair sense is from 1600s; in the 1811 "Dictionary of the Vulgar Tongue," the phrase
beard-splitter is defined as, "A man much given to wenching" (see
beaver).
"The Grecian beard was curly; the Roman, trimmed; but in the Roman Empire shaving became general about 450 B.C., partly for greater safety in close combat, not to be grasped by the beard. When Pope Leo III shaved, in 795, the Roman Catholic clergy followed his practice, and still generally do." [Shipley, p.28]