Anderson's Two Main Series

Regular blog readers probably know by now that my two favourite kinds of sf are future histories and time travel, although the latter has to be done either well or not all, and Poul Anderson presents multiple excellent examples of both. 

Future histories are one kind of fictional history. Fictional past histories include Middle Earth, Narnia and, I suggest, the Bible. I do not mean that the entire Bible is a work of fiction. However, it incorporates multiple genres, including myth, genealogy, theologically interpreted history, some works of historical fiction (Ruth, Jonah, Job) and apocalyptic future history.

Because future histories are fictional histories, because much of Anderson's time travel is to the past and because he also wrote both straight historical fiction and other kinds of historical sf, e.g., about immortals, it follows that historical processes became major themes in his works. The Roman Empire withdraws from Northern Europe and eventually falls just as the Terran Empire falls although between instalments. 

Anderson's two main series have to be the Technic History and the Time Patrol with The King Of Ys, co-written by Karen Anderson, as a close third. History, again. Which is better: the Technic History or the Time Patrol? This is not a comparison of like with like. Each excels in its own sub-genre. The Technic History is longer, seven omnibus volumes as against two, so it gives us more to reread. I cannot be 100% happy about Time Patrol treatment of causality violation but I am probably not going to be happy about anyone's treatment of that paradox. Skillful presentation of the circular causality paradox, which Anderson also does, is more intellectually satisfying.

In any case, my personal favourite series is the Technic History above any other.