The Cadfael Chronicles is a series of historical murder mysteries written by the linguist-scholar Edith Pargeter under the name "Ellis Peters". In all, Pargeter wrote twenty Cadfael novels between 1977 and 1994. Each draws upon the storyline, characters, and developments of previous books in the series. Pargeter apparently planned the 20th installment as the final book of the series; Brother Cadfael's Penance brings together the loose story ends into a tidy conclusion. Pargeter herself died shortly after its publication, following a long illness. Many of the books were adapted into both radio episodes in which Ray Smith, Glyn Houston and subsequently Philip Madoc played the monk, and a television series starring Derek Jacobi as Cadfael.