Saint Francis of Assisi 
Of Living Religiously in a Hermitage [EPUB ebook] 

Possessing nothing they wandered about like children careless of the day, teaching or preaching, passing the night in hay-lofts or under church porches, in lazarettos, or deserted huts and grottoes The need of having some kind of permanent retreat where they might retire at times to pray or rest, resulted in the institution of hermitages.