Many of Aiken's most popular books, including the Wolves Chronicles (also known as "The Wolves of Willoughby Chase" series or the James III series), are set in an elaborate alternative history of Britain in which James II was never deposed in the Glorious Revolution, but supporters of the House of Hanover continually agitate against the monarchy. These books also toy with the geography of London, adding a Canal District among other features. Wolves have invaded the country from Europe via the newly built Channel Tunnel. The novels share a varying cast and a variety of interlinked child protagonists – initially Bonnie Green, but subsequently her itinerant friend Simon, Simon's intrepid Cockney friend Dido Twite (the heroine of most of the books), Dido's half-sister Is and Owen Hughes (son of Dido's Royal Navy ally Captain Hughes).