Lizzie Bramlett recently did a post about pyjamas, citing 1912 as the earliest reference she has found to date for their sale in catalogues. This predates the c. 1917 date when they begin to show up more often in catalogues and magazines as sensible sleeping attire, especially for women in England in case of zeppelin raids. Bramlett also posted a 1919 pattern illustration for a sleeping pyjama intended for camping that looks a lot like a onesie. This might be the first of its kind!
When I first spotted this image of a woman in pyjamas I thought it was from the 1920s, but upon closer inspection you can see that the woman is running from a Zeppelin attack! The first successful raid on London by a Zeppelin occurred on May 31, 1915 and, as the text attests, fashion immediately stepped up with the idea of promoting pyjamas for women as a fashionable way to achieve the free movement needed in case of an emergency. I had never considered this as a reason for women’s pyjamas before, but here’s the proof!