Cover art
Bear, Greg. Eon. Translated to the German as Äon, Heyne 1987.

Bear, Greg. Eon
Divergence: 323 BCE
What if: Alexander the Great established a lasting empire.
Summary: An asteroid approaching our Earth turns out to contain artifacts from the future, but its presence inflames existing world tensions.
Series note: Somewhat more allohistorical sequel is Eternity, q.v. Non-allohistorical prequel is Legacy.
Comments: Allohistorical content appears only in epilog.
Published: Bluejay 1985 (0312941447); SFBC 1986; Tor 1986 (0812531701BUY), 1989 (0812505662BUY), 1995 (0812520475BUY); Gollancz 1986 (0575038616); Legend 1987 (0099523507), 1988 (0099547104); Gollancz/Vista 1998 (057560266X).
Original in: English.
Translation: Bulgarian by Julian Stoinov as [[title unknown]], [[publ. unknown]] 1995.
Translation: Nederlands by Thomas Wintner as Eon, Meulenhoff 1990 (9029043695).
Translation: French by Guy Abadia as Éon, Laffont 1989 (2221057406), Librairie generale française 1994 (2253071625).
Translation: German by Reinhard Heinz as Äon, Heyne 1987 (3453004507).
Translation: Italian by Gianluigi Ziddas as Eon, Nord 1987 (8842901849), 1992 (8842906859), 1998 (8842910392).
Translation: Spanish by Roger Voran de Parga as Eon, Ediciones B 1997 (8440672640), 1998 (8473864875).
Awards: Nominee: 1987 Arthur C. Clarke Award.

Bear, Greg. Eternity
Divergence: 323 BCE
Summary: More about the mysterious asteroid but includes further development of a world in which Alexander the Great lived longer.
Series note: Sequel to Eon.
Published: Warner 1988 (0446514020); SFBC 1988; Gollancz 1989 (0575041404, 0575046139); Popular Library/Questar 1989 (0445205474); Legend 1990 (009970630X); Warner/Aspect 1994 (0446601888BUY).
Original in: English.
Translation: Nederlands by Thomas Wintner as Eeuwigheid, Meulenhoff 1991 (9029043733).
Translation: French by Guy Abadia as Éternité, Laffont 1989 (222106478X), Librairie generale française 1994 (2253071641).
Translation: German by Winfried Petri as Ewigkeit, Heyne 1992 (3453058380).
Translation: Italian by Gianluigi Zuddas as Sfida all'eterntà, Nord 1989 (8842902020).
Translation: Spanish by Roger Voran de Parga as Eternidad, Ediciones B 1997 (8440673434).