Why was this flask made, and how was it used?
Medieval pilgrims, like tourists today, liked to take home souvenirs. So, when pilgrims traveled to the shrines of their favorite saints, they liked to bring back little tokens or mementos from their visits to the shrines of famous saints. Sometimes, these souvenirs were quite humble and easily portable—stones or pebbles taken from the vicinity, or bits of cloth touched by the holy relics. The officials in charge of the sites of saints’ cults, however, liked to control the business of pilgrims’ merchandise in order to keep hucksters at bay. For this reason, they promoted items such as badges, flasks, and medals, whose production they could license for a fee.
The pilgrim may have purchased the little flask already filled with blessed water. He or she also might have visited the cisterns at the site to have it filled. The blessed water was thought to have curative or apotropaic powers (i.e. it was able to ward off evil). The flask would have been sealed with a cork or a stopper, and it is likely that a cord was attached to the two handles so that the flask could be dangled around the neck.
Archaeologists have suggested that pilgrims’ souvenirs were sometimes ceremonially discarded when the pilgrim arrived home, in the same way that you might throw a coin into the Trevi Fountain in Rome. Many pilgrims’ badges, for example, have been found on the banks of the River Thames, near bridges.