Sometime in the 1960s, I think, I first read a collection of four novelettes by Poul Anderson called Guardians of time. They described the adventures of Manse Everard as an agent of the Time Patrol, a kind of police force formed in the far future to prevent or correct changes to human history caused by careless or malicious time travellers.
In 1977 I bought my own copy of the collection, and in 1983 I bought Time patrolman, containing two longer stories in the same series. In 1989 I bought a republished version of Guardians of time with an extra story in it. I've now bought a fat collection called Time Patrol, containing all the stories I had already plus three new ones: altogether, ten stories of varying lengths, 765 pages in total, written over a period of time stretching from 1955 to 1995.
The late Poul Anderson (1926-2001) wrote adventure stories, not high literature. However, for an old-time sf writer he wrote quite well, at least in his later years, and his love of history enabled him to give a good feel of time and place to his stories.
My favourite story here is ‘Delenda est’ (1955), in which a criminal gang goes back to 218 BC and helps Carthage to beat Rome in the Second Punic War. Because of this fundamental change in history, the Time Patrol is wiped out, except for those of its members who happened to be in pre-Roman times "when" the change occurred (any reference to time sequence is problematic in stories about time travel). A couple of them go forwards in time to 1960 AD for a holiday, and find themselves in a bizarrely changed world — the details of which add much interest and local colour to the story. They have to find out what happened, escape from custody, return to the Second Punic War, and defeat the criminals to restore their own history. By restoring their own history, they inevitably erase from existence all the innocent people of the alternative history (which they feel bad about).
My favourite of the new stories is ‘The year of the ransom’ (1988), in which another criminal gang tries to disrupt the events of 1533 AD, when the Incas amassed the great ransom demanded by Pizarro for their leader Atahualpa. In this case the attempt fails and history is not changed, so there are no fascinating details of alternative history here, but the story is entertaining. In the course of it, a bright 16th-century Spaniard hijacks a time hopper and makes quite a nuisance of himself.
Time hoppers are the time machines used by the Time Patrol; they resemble wheelless motorbikes and can move instantly to any location in time and space. Conveniently, they can also function as ordinary flying machines, hovering or zooming around. The power of the Time Patrol is, however, limited by severe undermanning: they have all of time to patrol and not many people to do it with, so they normally operate singly or in pairs.
If you read sf in general and time-travel stories in particular, I can recommend this collection; although the stories are somewhat uneven in style, mood, and length.
If you read the stories and like them, you can find three more of them in The shield of time.
Written in September 2007