E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Garter (g hard).
Knights of the Garter. The popular legend is that Joan, Countess of Salisbury, accidentally slipped her garter at a court ball. It was picked up by her royal partner, Edward III., who gallantly diverted the attention of the guests from the lady by binding the blue band round his own knee, saying as he did so, Honi soit qui mal y pense (1348).
Wearing the garters of a pretty maiden either on the hat or knee was a common custom with our forefathers. Brides usually wore on their legs a host of gay ribbons, to be distributed after the marriage ceremony amongst the bridegrooms friends; and the piper at the wedding dance never failed to tie a piece of the brides garter round his pipe. If there is any truth in the legend given above, the impression on the guests would be wholly different to what such an accident would produce in our days; but perhaps the Order of the Garter, after all, may be about tantamount to The Order of the Ladies Champions, or The Order of the Ladies Favourities.