Economic effect
As holy relics attracted pilgrims and these religious tourists needed to be housed, fed, and provided with souvenirs, relics became a source of income not only for the destinations that held them, but for the abbeys, churches, and towns en route. Relics were prized as they were portable. They could be possessed, inventoried, bequeathed, stolen, and smuggled. They could add value to an established site or confer significance on a new location. Offerings made at a site of pilgrimage were an important source of revenue for the community who received them on behalf of the saint. According to Patrick Geary, "[t]o the communities fortunate enough to have a saint's remains in its church, the benefits in terms of revenue and status were enormous, and competition to acquire relics and to promote the local saint's virtues over those of neighboring communities was keen". Local clergy promoted their own patron saints in an effort to secure their own market share. On occasion guards had to watch over mortally ill holy men and women to prevent the unauthorized dismemberment of their corpses as soon as they died. Geary also suggests that the danger of someone murdering an aging holy man in order to acquire his relics was a legitimate concern.
Relics were used to cure the sick, to seek intercession for relief from famine or plague, to take solemn oaths, and to pressure warring factions to make peace in the presence of the sacred. Courts held relics since Merovingian times. St. Angilbert acquired for Charlemagne one of the most impressive collections in Christendom. An active market developed. Relics entered into commerce along the same trade-routes followed by other portable commodities. Matthew Brown likens a ninth-century Italian deacon named Deusdona, with access to the Roman catacombs, as crossing the Alps to visit monastic fairs of northern Europe much like a contemporary art dealer.
Canterbury was a popular destination for English pilgrims, who traveled to witness the miracle-working relics of Thomas Becket, the sainted archbishop of Canterbury who was martyred at the hands of knights of King Henry II in 1170. When Becket was martyred, his successor and the Canterbury chapter quickly used his relics to promote the cult of the as yet un-canonized martyr. The motivations included the assertion of the Church's independence against rulers, a desire to have an English (indeed Norman English) saint of European reputation, and the desire to promote Canterbury as a destination for pilgrimage. In the first years after Becket's death, donations at the shrine accounted for twenty-eight percent of the cathedral's total revenues.
In art
Many churches were built along pilgrimage routes. A number in Europe were either founded or rebuilt specifically to enshrine relics, (such as San Marco in Venice) and to welcome and awe the large crowds of pilgrims who came to seek their help. Romanesque buildings developed passageways behind the altar to allow for the creation of several smaller chapels designed to house relics. From the exterior, this collection of small rooms is seen as a cluster of delicate, curved roofs at one end of the church, a distinctive feature of many Romanesque churches. Gothic churches featured lofty, recessed porches which provided space statuary and the display of relics.
Historian and philosopher of art Hans Belting observed that in medieval painting, images explained the relic and served as a testament to its authenticity. In Likeness and Presence, Belting argued that the cult of relics helped to stimulate the rise of painting in medieval Europe.
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Counterfeits
In the absence of real ways of assessing authenticity, relic-collectors became prey to the unscrupulous, and some extremely high prices were paid. Forgeries proliferated from the very beginning. Augustine denounced impostors who wandered around disguised as monks, making a profit from the sale of spurious relics. In the Admonitio Generalis of 789, Charlemagne ordered that "the false names of martyrs and the uncertain memorials of saints should not be venerated". The Fourth Lateran Council (1215) the Church condemned such abuses such as counterfeit relics and exaggerated claims.
Pieces of the True Cross were one of the most highly sought after such relics; many churches claimed to possess a piece of it, so many that John Calvin famously remarked that there were enough pieces of the True Cross to build a ship from, although a study in 1870 found that put together the claimed relics of the cross at that time weighed less than 1.7 kg.
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The sale of relics is strictly forbidden by the Church. The Code of Canon Law states:[34]
§1190 §1 – "It is absolutely forbidden to sell sacred relics."
§1190 §2 – "Relics of great significance and other relics honored with great reverence by the people cannot be alienated validly in any manner or transferred permanently without the permission of the Apostolic See."