Between the ninth and twelfth centuries, the practice of stealing holy relics was rampant in Europe. Monks, priests, nuns, and even bishops were willing to break one of the commandments in order to possess even a small piece of some martyred saint's remains. Sure, a relic could produce miracles, but one would also be valuable to the monastery's prestige and even tourism business for the entire region.
Perhaps the strangest thing about relic theft is how open monks were about their capers. In fact, we know about it mostly because they wrote about it, quite unabashedly. There was a whole genre devoted to the topic of furta sacra (holy theft). Scholars contend that many of these tales were exaggerated or even fabricated outright. But that only makes the problem more perplexing. It’s strange enough to cheerfully confess that you or one of your brothers stole a holy relic. It’s even stranger to say so if you actually didn’t.
There are a few explanations. First of all, a story of theft could give an otherwise dubious relic a plausible backstory. Or the story could cover up other means of acquisition: theft might actually be preferable to commerce, which crassly reduced holy saints to the status of commodities.
Read about the era of relic theft and the justifications for it at JStor Daily. -via Damn Interesting