Cover art
Anderson, Poul. Guardians of Time. Pan 1977.
Cover art
Anderson, Poul. The Time Patrol. Tor 1991.
Cover art
Anderson, Poul. Time Patrol. Baen 2006.
Cover art
Anderson, Poul. The Time Patrol. Translated to the German as Die Chroniken der Zeitpatrouille. Heyne 1997.

Anderson, Poul. The Time Patrol
Summary: Time cops patch up history.
Series note: Many-storied series, but the only entries with explicit allohistorical content are "Delenda Est" and The Shield of Time. Other entries in series are "Time Patrol", "Brave to be a King", "The Only Game in Town", "Gibraltar Falls", "Ivory, and Apes, and Peacocks", "The Sorrow of Odin the Goth", "Star of the Sea", and "The Year of the Ransom", and "Death and the Knight".
Published: All of the short stories are gathered in Time Patrol, Baen 2006 (1416509356BUY). All but "Death and the Knight" are gathered in The Time Patrol, Tor 1991 (0312852312BUY), 1994 (0312856369BUY), SFBC 1991. Other, earlier collections with some smaller subset of the stories include Guardians of Time, Ballantine 1960, Gollancz 1961, Pan 1964, 1977 (0330016601), exp Tor 1981, 1988 (0812530918); Time Patrolman, Tor 1983, Sphere 1986 (0722112904), 1988 (0722112904); and Annals of the Time Patrol, SFBC 1984.
Original in: English.
Translation: Nederlands of Guardians of Time by P. Groen as Avontuur in het Verleden, Het Spectrum 1966, 1984 (9027414068), Het Spectrum/Prisma 1987.
Translation: French of Guardians of Time by Bruno Martin, Michel Deutsch, and Roger Durand as La patrouille du temps, Marabout 1965, 1978, J'ai lu 1982 (2277214094).
Translation: German of Guardians of Time by Heinz Bingenheimer as Hueter der Zeiten, Goldmann 1963.
Translation: German of Time Patrolman by Hans Maeter as Zeitpatrouille, Heyne 1987 (345331381X).
Translation: German by Hans Maeter and Peter Pape as Die Chroniken der Zeitpatrouille, Heyne 1997 (3453119460).
Translation: Italian of Guardians of Time by Andreina Negretti as Nella Trama del Tempo, Mondadori 1961. V.t. I guardiani del Tempo, Mondadori 1977.
Translation: Italian of Time Patrolman by Andreina Negretti as La Pattuglia del tempo, Mondadori 1994 (8804377593), Mondadori 1995 (8804403462).
Translation: Portuguese of Time Patrolman by Maria José Bellino Machado as Patrulheiro do tempo, Europa-América 1989 (9721028053).
Translation: Romanian of Time Patrolman by Gabriel Stoian as Patrula Timpului, Nemira 1994.
Translation: Russian of Time Patrol by N. Naumenko et al. as Patrul' vremeni, Eksmo 2004.
Translation: Spanish of Time Patrol and The Shield of Time by Pedro Jorge Romero as La Patrulla del Tiempo, Ediciones B 2000 (8440697236).

Anderson, Poul. "Delenda Est"
Divergence: 218 BCE
What if: The Scipios were killed at Ticinus, and Hannibal later captured and destroyed Rome.
Summary: Celts are driving steamcars in 1955 "New York"; it's up to Time Patrolman Manse Everard to go back to the Second Punic War and set things right.
Series note: A Time Patrol story.
Published: In The Magazine of Fantasy and Science Fiction, December 1955; Guardians of Time, Ballantine 1960, Gollancz 1961, Pan 1964, Pan 1977 (0330016601), exp Tor 1981, Tor 1988 (0812530918); Worlds of Maybe: Seven Stories of Science Fiction (ed. Robert Silverberg), q.v.; Annals of the Time Patrol, SFBC 1984; Time Wars (eds. Poul Anderson, Charles G. Waugh and Martin H. Greenberg), Tor 1986 (0812530489, 0812530497); Alternative Histories: Eleven Stories of the World as It Might Have Been (eds. Charles G. Waugh and Martin H. Greenberg), q.v.; Isaac Asimov Presents the Great SF Stories: 17 (1955) (eds. Isaac Asimov and Martin H. Greenberg), DAW 1988 (0886772567); The Eternal City (ed. David Drake, Martin H. Greenberg and Charles G. Waugh), Baen 1990 (0671698575) The Time Patrol, Tor 1991 (0312852312BUY), 1994 (0312856369BUY), SFBC 1991; One Lamp: The Best Alternate History Stories from F&SF (ed. Gordon Van Gelder), q.v.; and Time Patrol, Baen 2006 (1416509356BUY).
Original in: English.
Translation: Nederlands by P. Groen as "Delenda Est", in Avontuur in het Verleden, Het Spectrum/Prisma 1966, 1984 (9027414068), 1987.
Translation: French as "L'autre univers", in La Patrouille du temps, J'ai lu 1960, Marabout 1978, J'ai lu 1982 (2277214094).
Translation: German by Heinz Bingenheimer without title, in H&#uuml;ter der Zeiten: Ein utopisch-technischer Roman, Goldmann 1961, 1963.
Translation: German by Hans Maeter as "Delenda Est", in Zeitpatrouille, Heyne 1987 (345331381X); and Die Chroniken der Zeitpatrouille, Heyne 1997 (3453119460).
Translation: Italian by Andreina Negretti as "Il mondo che non poteva esistere", in Nella Trama del Tempo, Mondadori 1961; I guardiani del Tempo, Mondadori 1977; and La Pattuglia del tempo, Mondadori 1994 (8804377593), Mondadori 1995 (8804403462).
Translation: Italian by Giampaolo Cossato and Sandro Sandrelli as "Delenda est", in Le grandi storie della fantascienza 17 (eds. Isaac Asimov and Martin H. Greenberg), Armenia 1988 (8834403320), Bompiani 1999 (8845239829).
Translation: Portuguese by Reinaldo Guarany as "Delenda Est", in Os Guardiões do Tempo, Francisco Alves (1984).
Translation: Russian by N. Naumenko as "Delenda Est", in Patrul' vremeni, Eksmo 2004.

Cover art
Anderson, Poul. The Shield of Time. Tor 1991.

Anderson, Poul. The Shield of Time
Divergence: 1137 CE
Summary: Manse Everard and Wanda Tamberley patch history up at Bactra (209 BCE) and Rignano (1137 CE).
Series note: The only novel-length entry in the Time Patrol series.
Published: Tor 1990 (0312850883BUY), 1991 (0812510003BUY); SFBC 1990.
Original in: English.
Translation: German by Edda Petri as Der Schild der Zeit, Heyne 1993 (3453062035).
Translation: Spanish by Pedro Jorge Romero, included in La Patrulla del Tiempo, Ediciones B 2000 (8440697236).