 Various legends account for the origin of the Order . The most popular legend involves the " Countess of Salisbury " ( either Edward 's future daughter @-@ in @-@ law Joan of Kent or her former mother @-@ in @-@ law , Catherine Montacute , Countess of Salisbury ) . While she was dancing at a court ball at Calais , her garter is said to have slipped from her leg . When the surrounding courtiers <unk> , the king picked it up and returned it to her , exclaiming , " Honi soit qui mal y pense " ( " Shame on him who thinks evil of it . " ) , the phrase that has become the motto of the Order . 
