As time went on, the monasteries were just coining in money. After all, they held the keys to heaven, and everyone wants to get there. So they developed many ways to part the rich from their cash.
For example, the medieval church advised that everyone go on a pilgrimage at least once in their lifetime. It was good for the soul, and it made the church a lot of money. Monastic institutions up and down the land vied with each other to attract the most visitors. The best bet was to have a really first-class relic. Canterbury Cathedral made more than a thousand pounds a year out of a pilgrimage. Of course, the big attraction there was the skull of Thomas Beckett, the turbulent priest who’d challenged the power of King Henry II. You could see where his head had been split in two.
But monks of Canterbury had plenty of other relics to be proud of:
There was Aaron’s rod.
There was some of the stone on which Jesus was standing shortly before He ascended into heaven.
There was part of the table at which the Last Supper was eaten.
They even had some of the clay out of which God fashioned Adam.
And some of the Virgin Mary’s knitting.
And we know all of this because a writer in the 15th century carefully noted it all down.