Pilgrimage played a central role of the beliefs and religious life of medieval men and women. The most celebrated shrines of international importance were visited by pilgrims from all over the Catholic world. In the Nordic countries, Nidaros (Trondheim) and Vadstena in Sweden were the most famous. The visiting pilgrims were of course an important source of income for a church, through increased offertories and votive gifts. An additional profit could be made through the sale of small metal badges, which were worn as the visible proof of completed pilgrimage. The earliest examples of these pilgrim¹s badges date from the twelfth century and have been found on the European continent, but they became most popular during the fourteenth and fifteenth centuries. Pilgrim¹s badges were also used as models for decorative reliefs on late medieval church bells. Because many church bells were inscribed with the exact date of manufacture, they can provide important evidence for the dating of badges.
The badge from Nidaros depict Saint Olav in a seated or standing position, with an axe in one hand and, usually, a crowned orb in the other. We know currently of eight finds of original badges, seventeen examples of reliefs on church bells, and one fragementary mould. Within this group, eight different designs can be destinguished. Those badges which can be dated belong to a period of ninety years, between 1433 and 1523. Thus, the pilgrim¹s badges from Nidaros were a late medieval occurrence.
However, this does not imply that the shrine was of less importance as a destination for pilgrims in the earlier period, but only that there was no commerce in such souvenirs in Scandinavia until the late middle ages. The find-spots of the preserved badges indicate that the pilgrims came mainly from Norway and the neighbouring Nordic countries.
Besides the metal badges, a particular type of miniature stoneware jars has been found in western Scandinavia, which although their main function was secular, were also used in religious contexts. One such jar, found in Saint Olav¹s spring in the cathedral of Nidaros, indicates that pilgrims either brought such jars with them, or purchased them at the shrine and filled them with miraculous water to take home.

Source:
Helgonet i Nidaros
Olavskult och kristnande i Norden
Riksarkivet 1997.