E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
i.e. cord - wearers, 1215. A religious order of the Minor Brothers of St. Francis Assisi. They wore a large grey cloth vestment, girt about the loins with a rope or cord. It was one of the mendicant orders, not allowed to possess any property at all; even their daily food was a gift of charity. The Cordeliers distinguished themselves in philosophy and theology. Duns Scotus was one of their most distinguished members.
The tale is that in the reign of St. Louis these Minorites repulsed an army of infidels, and the king asked who those gens de cordelies (corded people) were. From this they received their appellation.