A Morbid Taste For Bones
by Ellis Peters. This is the first in a series of mystery books set in the 12th Century. The
protagonist is one Brother Cadfael, a 50-ish Benedictine brother who "took up the cowl" later in
life after many worldly experiences, including fighting in the Crusades.
The book was very good and easily readable. The story was about an errand to procure the relics of a St. Winifred from Wales to bring back to their English abbey. This causes a problem with the local parishioners and one of the most vocal opponents is murdered. Brother Cadfael uses practical reasoning and detective work to figure out the mystery.
A BBC series was made from these books, with Derek Jacobi ("I Claudius" fame) playing the main character..