We think of a hermit as someone who withdraws from society, who perhaps has some sort of psychological problem (afraid of crowds, bad social skills). Or perhaps we think of the cartoon wise man (guru) living on top of a mountain. In the Middle Ages, hermits withdrew from society for religious reasons, to devote their lives to prayer and contemplation.
As I discussed in an earlier post on monasteries, monks and hermits began in Egypt in the third century with Saint Anthony—if you're named Tony or Antonia, you're ultimately named for him. Hermits came first, men (rarely women) who went out into the desert to live an extremely simple life of prayer. People did come to seek their wisdom, which was usually along the lines of giving up sin and purifying oneself for God.
Because it is easier to keep to a life of radical prayer and asceticism if one has helpers to nudge you back in line if you start to drift, many hermits started gathering together in groups, under a master or abbot. Both forms of life, the solitary hermit version and the monks in groups version (eremetism and cenobitism if you're keeping score at home) continued during the Middle Ages.
It was hard to be a hermit (which of course was the idea). Even beyond what must have been the constant temptation to think, "What am I doing? Why don't I go back to town and see my friends for a change?" there was the basic difficulty of getting enough to eat. Hermits settled by preference in wild, solitary places, which meant they would have difficulty growing crops. There were nuts and berries, but these only go so far. Essentially hermits were dependent on people coming by and making gifts.
In the Egyptian desert of late antiquity, the hermits became something of a tourist attraction, and people would come from as far away as Jerusalem to visit them. Some hermits made simple objects like sandals or prayer mats from palm fronds and sold them to the tourists. But chatting with tourists sort of undercuts the whole solitary-prayer thing. Some hermits wouldn't come out of their cells and just had to hope the tourists would drop off some food before leaving in frustration.
In the early Middle Ages, when the economy was very tight, it was hard for anyone to make a living, much less a hermit. But when the economy started booming in the eleventh and twelfth centuries, leaving the world and its comforts for radical simplicity and solitude became not just possible but appealing. Most new twelfth-century monasteries had their origins in hermitages, where an original solitary had gathered a small group of followers.
This was the problem of being a holy hermit. "He lives all by himself, he is so holy, he understands the ways of God, being so solitary," people would say. "Let's make him lavish gifts and go live with him."
Because I try to include at least some real medieval history in my fantasies, I have a hermit—with apprentices—in The Wood Nymph and the Cranky Saint. They live at the shrine of a long-dead, sainted hermit, the Cranky Saint himself.
The book is available as an ebook from Amazon and other ebook stores, as well as an audio book.