The recorded history of armpit shaving is a spotty one indeed. The earliest reference we have found was that the ancient Babylonians, more than one thousand years before the birth of Christ, developed depilatories to remove unwanted body hairs.
Julius Caesar reported that early Britons “had long flowing hairs and shaved every part of their bodies except the head and upper lip”, but this quotation may refer only to men. We do know that barbers removed superfluous hair from the eyebrows, nostrils, arms, and legs from male customers around this time.
Strict Muslims removed all body hair below the neck, both men and women. It’s seen as an act of religious purity. The practice dates back at least to the 8th C.
American women had no need to shave their underarms before about 1915 ““ after all, who ever saw them? Even the word “underarm” was considered scandalous, what with it being so near certain other interesting body parts. Then came the sleeveless dress. An ad in the fashion mag Harper’s Bazaar decreed that to wear it (and certainly to wear it while participating in “Modern Dancing”), women would need to first see to “the removal of objectionable hair.” They didn’t need much convincing, and by the early ’20s, hairy underarms were so last decade, at least in America.