The Novels

  Cradle of the Sun (1969)
  The Blind Worm (1970)

Dies Irae:

 The Days of Glory (1971)

Dies Irae:

 In the Kingdom of the Beasts (1971)

Dies Irae:

 Day of Wrath (1971)
  To Challenge Chaos (1972)

Hooded Swan:

 Halcyon Drift (1972)

Hooded Swan:

 Rhapsody in Black (1973)

Hooded Swan:

 Promised Land (1974)

Hooded Swan:

 The Paradise Game (1974)

Hooded Swan:

 The Fenris Device (1974)

Hooded Swan:

 Swan Song (1975)
  The Realms of Tartarus (1977)
  - The Face of Heaven (1976)
  - A Vision of Hell (1979)
  - A Glimpse of Infinity (1979)
  Man in a Cage (1976)
  The Mind-Riders (1976)

Daedalus:

 The Florians (1976)

Daedalus:

 Critical Threshold (1977)

Daedalus:

 Wildeblood's Empire (1977)

Daedalus:

 The City of the Sun (1978)

Daedalus:

 Balance of Power (1979)

Daedalus:

 The Paradox of the Sets (1979)
  The Last Days of the Edge of the World (1978)
  The Walking Shadow (1979)
  Optiman (1980) aka War Games in the UK.
  The Castaways of Tanagar (1981)
Asgard 1:
 Journey to the Center (1982) aka Asgard's Secret
  The Gates of Eden (1983)
  The Empire of Fear (1988)

Asgard 2:

 Invaders from the Centre (1990) aka Asgard's Conquerors

Asgard 3:

 The Centre Cannot Hold (1990) aka Asgard's Heart

Orfeo:

 Zaragoz (1989) as Brian Craig

Orfeo:

 Plague Dæmon (1990) as Brian Craig

Orfeo:

 Storm Warriors (1991)as Brain Craig

Werewolves:

 The Werewolves of London (1990)

Werewolves:

 The Angel of Pain (1991)

Werewolves:

 The Carnival of Destruction (1994)
  Ghost Dancers (1991) as Brian Craig
  Young Blood (1992)
  Firefly: A Novel of the Far Future (1994)

Genesys:

 Serpent's Blood (1995)

Genesys:

 Salamander's Fire (1996)

Genesys:

 Chimera's Cradle (1997)
  The Hunger and Ecstasy of Vampires (1996)

Emortality 2:

 Inherit the Earth (1998)

Emortality 4:

 Architects of Emortality (1999)

Emortality 5:

 Fountains of Youth (2000)

Emortality 1:

 The Cassandra Complex (2001)

Emortality 3:

 Dark Ararat (2002)

Emortality 6:

 The Omega Expedition (2002)
  Year Zero (2000)
  The Wine of Dreams (2000) as Brian Craig
  Pawns of Chaos (2001) as Brian Craig
  The Eleventh Hour (2001)
  Curse of the Coral Bride (2005)
  Kiss the Goat (2005)