A shoemaker. St. Crispin was a shoemaker, and was therefore chosen for the patron saint of the craft. It is said that two brothers, Crispin and Crispian, born in Rome, went to Soissons, in France (A.D. 303), to propagate the Christian religion, and maintained themselves wholly by making and mending shoes. Probably the tale is fabulous, for crepis is Greek for a shoe, Latin crepid-a, and St. Crepis or Crepid became Crepin and Crespin.
And Crispin Crispian shall ne'er go by ... But we in it shall be remembered.
Shakespeare: Henry V., iv. 3.
The French argot for a leather purse is une crépine.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894