* _The Reluctant Knight_ (1970)
* _Rebellion in the Midlands_ (1980)
* _The Book of Kells_ (1984)
* _Kongens datter_ (1988)
* _Det lange sværd_ (1991)
* _Skovkongen_ (1994)
* _Knights of Camelot_ (1997)
* _Ravnens skygge_ (2000)
* _The Last of the Druids_ (2003)
* _The Lion of Ireland_ (2006)
Faglitteratur:
* _Historien om Irland_ (1982)
* _Vikingerne i Irland_ (1988)
* _The High Kings of Ireland_ (1994)
* _Den keltiske verden_ (1998)
* _The Age of Arthur_ (2001)
* _Irlands historie_ (2004)
* _The Tudors in Ireland_ (2007)
* _The Stuarts in Ireland_ (2010)
* _Hanoverianerne i Irland_ (2013)
* _Briterne i Irland_ (2016)