When on duty they wear black robes and hoods.

Their headquarters comprise a chapel, with an altar by Andrea della Robbia, and a statue of the patron saint of the Misericordia, S.Sebastian.But their real patron saint is their founder, a common porter named Pietro Borsi.

In the thirteenth century it was the custom for the porters and loafers connected with the old market to meet in a shelter here and pass the time away as best they could.

Borsi, joining them, was distressed to find how unprofitable were the hours, and he suggested the formation of a society to be of some real use, the money to support it to be obtained by fines in payment for oaths and blasphemies.

A litter or two were soon bought and the machinery started.