According to the legend, St. James made a missionary voyage to Spain soon after Pentecost. This was James the brother of St. John and the son of Zebedee. On James’s return to Jerusalem, he suffered martyrdom. His followers put his body in a coffin and sailed off to bury him in Spain.
As they approached the coast of Spain, James – from his coffin – saved a man who had been carried into the sea by a frightened horse. When horse and rider emerged from the sea, they were covered with scallop shells. Because of this legend the scallop shell is the symbol of St. James.
The scallop shell is also the symbol of all pilgrims who visit his shrine in Spain. It is called Santiago de Compostela (Santiago is “St. James” in Spanish).