Frank Bottomley is a medieval and local historian concentrating on Yorkshire, England. His monograph “Yorkshire’s Spiritual Athletes: Hermits & Other Solitaries” is a wonderful resource which he makes available free at his website. (The text appears complete in the main link, but the appendices only include one of several projected items in the table of contents.) The work extends the detail of venerable predecessors like Rotha Mary Clay’s Hermits and Anchorites of England.
URL: http://dryfish.org.uk/~medieval/
and main text directly at http://www.zurgy.org/medieval/hermits.pdf