Cover art
Turtledove, Harry. Worldwar: In the Balance. Ballantine/Del Rey 1994 (cover art by Bob Eggleton).
Cover art
Turtledove, Harry. Worldwar: In the Balance. Translated to the Russian as Flot vtorshcheniya (vol. 1), Machaon 2001.

Turtledove, Harry. Worldwar & Colonization.
Series note: Eight related volumes, comprising either one large series or else two connected smaller series and an epilogue, depending on how you count. Begins with the Worldwar tetralogy, including In the Balance, Tilting the Balance, Upsetting the Balance, and Striking the Balance. Set 20 years later is the Colonization trilogy, including Second Contact, Down to Earth, and Aftershocks. The epilogue is Homeward Bound.
Divergence: 1942 CE
What if: A space alien invasion force arrived on Earth in late May 1942.

Cover art
Turtledove, Harry. Worldwar: Tilting the Balance. Ballantine/Del Rey 1995 (cover art by Stan Watts).
Cover art
Turtledove, Harry. Worldwar: Striking the Balance. Ballantine/Del Rey 1996 (cover art by Stan Watts).
Cover art
Turtledove, Harry. Colonisation: Second Contact. Hodder & Stoughton 1999 (cover art by Fred Gambino).
Cover art
Turtledove, Harry. Colonization: Aftershocks. Ballantine/Del Rey 2001 (cover art by Viktor Koen).
Cover art
Turtledove, Harry. Homeward Bound. Ballantine/Del Rey 2005.

Turtledove, Harry. Worldwar.
Series note: Initial tetralogy of the Worldwar & Colonization sequence. Includes In the Balance, Tilting the Balance, Upsetting the Balance, and Striking the Balance.

Original in: English.
Translation: Italian of complete tetralogy by Gianluigi Zuddas as Worldwar: La seconda guerra mondiale che non si è mai combattuta, Nord 1997 (8842909882).
Awards: Honorable mention: 1996 Sidewise Award for best long-form alternate history.

Turtledove, Harry. Worldwar: In the Balance.
Series note: Volume one of Worldwar.
Divergence: 1942 CE
Summary: Surprised to find Earth's technology so advanced after a reconnaisance probe visited 800 years before, the lizard-like aliens still invade, forcing odd alliances between enemies.

Published: Ballantine/Del Rey 1994 (0345382412), 1995 (0345388526); SFBC 1994; Hodder & Stoughton 1994 (0340624906); and New English Library 1994 (0340618396).
Original in: English.
Translation: Italian by Gianluigi Zuddas as Invasione: anno zero, Nord 1995 (8842908738), TEA 2004.
Translation: Polish by Antoni S. Kowal as Wojna swiatow: w rownowadze, Wydawnictwo Amber 1997.
Translation: Russian by [[trans. unknown]] as Flot vtorshcheniya, Machaon 2001 (in two volumes).
Bookstore: Listed by Amazon.com in paperback.

Turtledove, Harry. Worldwar: Tilting the Balance.
Series note: Volume two of Worldwar.
Divergence: 1942 CE
Summary: The fight rages on into 1943, with beleaguered humanity pushing harder to exploit captured uranium.

Published: Ballantine/Del Rey 1995 (0345389972), 1996 (0345389980); Hodder & Stoughton 1995 (0340632399); SFBC 1995; and New English Library 1995 (0340648996).
Original in: English.
Translation: Italian by Gianluigi Zuddas as Invasione: fase seconda, Nord 1996 (8842909319), TEA 2004.
Translation: Russian by [[trans. unknown]] as Otvetnii chdar, Machaon 2003.
Bookstore: Listed by Amazon.com in paperback.

Turtledove, Harry. Worldwar: Upsetting the Balance.
Series note: Volume three of Worldwar.
Divergence: 1942 CE
Summary: 1943 comes to a close with humanity slowly gaining ground against the Lizards after several nuclear exchanges.

Published: Ballantine/Del Rey 1996 (0345402219), 1996 (0345402405); Hodder ∧ Stoughton 1996 (0340666978); SFBC 1996; and New English Library 1996 (0340666986).
Original in: English.
Translation: Italian by Gianluigi Zuddas as Invasione: atto terzo, Nord 1996 (884290953X), TEA 2004.
Bookstore: Listed by Amazon.com in paperback.

Turtledove, Harry. Worldwar: Striking the Balance.
Series note: Volume four of Worldwar.
Divergence: 1942 CE
Summary: The war between humans and Lizards slowly culminates in a series of negotiated peaces.

Published: Ballantine/Del Rey 1996 (0345405501), 1997 (0345412087); Hodder & Stoughton 1996 (0340684909); SFBC 1997; and New English Library 1997 (0340684917).
Original in: English.
Translation: Italian by Gianluigi Zuddas as Invasione: atto finale, Nord 1997 (8842909734).
Bookstore: Listed by Amazon.com in paperback.

Turtledove, Harry. Colonization.
Series note: A three-volume sequel to the story begun in Worldwar, and making up the fifth through seventh volumes of Worldwar & Colonization. Includes Colonization: Second Contact, Colonization: Down to Earth, and Colonization: Aftershocks.
Divergence: 1942 CE
Summary: Twenty years after the Lizard invasion force attacked Earth, the colonization fleet arrives.

Turtledove, Harry. Colonization: Second Contact.
Series note: First volume of Colonization, or fifth of Worldwar & Colonization.
Divergence: 1942 CE
Summary: The Lizard colonization fleet arrives at Earth in 1961 and finds it only partially subjugated. Despite a sneak attack on the fleet, colonization begins and runs into trouble when it is discovered that a common herb radically alters the Lizard reproductive cycle.

Published: Ballantine/Del Rey 1999 (0345430190), 2000 (0345430220). V.t. Colonisation: Second Contact, Hodder & Stoughton 1999 (0340751436); New English Library 2000 (0340751444).
Original in: English.
Translation: Italian by Carlo Boriello as Colonizzazione: Fase 1, Fanucci 1999 (8834706366), 2002.
Bookstore: Listed by Amazon.com in hardcover and in paperback.

Turtledove, Harry. Colonization: Down to Earth.
Series note: Second volume of Colonization, or sixth of Worldwar & Colonization.
Divergence: 1942 CE
Summary: A year of Lizards and humans slowly adjusting to each other instead ends in confusion when the death of Reichführer Himmler leads to returned Nazi designs on Lizard-occupied Polish territory.

Published: Ballantine/Del Rey 2000 (0345430204), 2001 (0345430239). V.t. Colonisation: Down to Earth Hodder & Stoughton 2000 (0340768681); New English Library 2000 (034076869X).
Original in: English.
Translation: Italian by Carlo Boriello as Colonizzazione: Fase 2, Fanucci 2000.
Bookstore: Listed by Amazon.com in hardcover and in paperback.

Turtledove, Harry. Colonization: Aftershocks.
Series note: Third and final volume of Colonization, or seventh but not final of Worldwar & Colonization.
Divergence: 1942 CE

Published: Ballantine/Del Rey 2001 (0345430212), 2002 (0345430247).
Original in: English.
Translation: Italian by [[trans. unknown]] as Colonizzazione: Fase 3, Fanucci 2001.
Bookstore: Listed by Amazon.com in hardcover and in paperback.

Turtledove, Harry. Homeward Bound.
Series note: Epilogue eighth volume to the Worldwar & Colonization series.
Divergence: 1942 CE

Published: Ballantine/Del Rey 2005 (034545846X); and Hoddard & Stoughton 2005 (0340734833).
Bookstore: Listed by Amazon.com in hardcover.