From the introduction: Cthulhu Dark Ages is Chaosium’s Middle Age’s [sic] supplement for the Call of Cthulhu Role-Playing Game line. Written by Stéphane Gesbert, and originally published as Cthulhu 1000AD by Pegasus Spiele, it explores the Lovecraft mythos set in the early medieval era. This document, Cthulhu Dark Ages: Guide to England, suggests additions and changes to the setting’s rules and highlights, albeit briefly, life in England during this period.