The scallop shell, often found on the shores in Galicia, has long been the symbol of the Camino de Santiago. Over the centuries the scallop shell has taken on a variety of meanings, metaphorical, practical, and mythical, even if its relevance may have actually derived from the desire of pilgrims to take home a souvenir. According to Spanish legends, Saint James had spent time preaching the gospel in Spain, but returned to Judaea upon seeing a vision of the Virgin Mary on the bank of the Ebro River.
From its connection to the Camino, the scallop shell came to represent pilgrimage, both to a specific shrine as well as to heaven, recalling Hebrews 11:13, identi- fying that Christians "are pilgrims and strangers on the earth".
The scallop shell is the traditional emblem of St James the Great and is popular with pilgrims returning from the Way of St James (Camino de Santiago) and the apostle's shrine at Santiago de Compostela in Galicia, Spain.
Medieval Christians would collect a scallop shell while at Compostela as evidence of having made the journey. The association of Saint James with the scallop can most likely be traced to the legend that the apostle once rescued a knight covered in scallops. An alternative version of the legend holds that while St. James' remains were being transported to Galicia (Spain) from Jerusalem, the horse of a knight fell into the water, and emerged covered in the shells.
Indeed in French the mollusc itself – as well as a popular preparation of it in cream sauce – is called coquille St. Jacques. In German they are Jakobsmuscheln – literally "James's shellfish".
A marker in the pavement indicates the route of the Way of St James through Navarrete, La Rioja, Spain
The scallop shell is an ubiquitous sight along the Camino, where it often serves as a guide for pilgrims. The shell is even more commonly seen on the pilgrims themselves, who are thereby identified as pilgrims. Most pilgrims receive a shell at the beginning of their journey and display it throughout their journey.
During the medieval period, the shell was more a proof of completion than a symbol worn during the pilgrimage.
Created and established after the discovery of the relics of James of Zebedee at the beginning of the 9th century, the Way of St James became a major pilgrimage route of medieval Christianity from the 10th century onwards. But it was only after the capture of Granada in 1492, under the reign of Ferdinand II of Aragon and Isabella I of Castile, that Pope Alexander VI officially declared the Camino de Santiago to be one of the "three great pilgrimages of Christendom", along with Jerusalem and Rome.