This article examines the historical fantasy world created by Joan Aiken in the eleven volumes of her "Wolves of Willoughby Chase" series. In particular it looks at her subversion of historical reality by the creation of an alternative yet recognisable representation of our own world, using a wide range of events, and the remoulding of aspects of language and geography. It also discusses her reasons for writing in this form and explores the character of Dido Twite as heroine and major raison d'etre of the series.