They are pilgrims. In the Middle Ages,it was customary for groups of people to travel together - safety in numbers to avoid robbers on the road - to various shrines around the country. There would be a monument to a saint, often with relics including bones that were supposedly from the saint's body, or a splinter from the 'true cross'. Having visited, and said their prayers, the pilgrims would be assured of a higher place in heaven, and a shorter stay in purgatory.