The shell: its relationship to Santiago and to pilgrimages
The shell, as an emblem of pilgrimage, "signum peregrinorum", has been in use since at least the twelfth century, but despite other pagan and Christian uses throughout the centuries, it began to develop enormously in the medieval period as a heraldic element, a symbol of Santiago : of its cathedral, its city, its pilgrims ... The scallop shell became synonymous with Santiago and was used on the facades of palaces, as well as on coats of arms and on tombstones.