Poul Anderson's Two Main Bodies Of Work

I think that there is no doubt that Poul Anderson's two main bodies of work are the Time Patrol series, complete in one omnibus collection and one long, tripartite novel, and the History of Technic Civilization, complete in seven omnibus collections. The difference is quantitative but not qualitative.

Both series are reflections on historical processes and on the passage of time. They are complementary to the extent that they address the past and a future, respectively, although not in a single timeline. A multi-dimensional framework would be able to incorporate the events of both series. This is not necessary for either narrative although it is indicated elsewhere.

Both series are conservative. The Time Patrol conserves the course of history that leads to the post- and super-human Danellians. In the Technic History, Nicholas van Rijn's Solar Spice & Liquors Company needs stable governments to facilitate trade. Van Rijn is not above overthrowing an unhelpful government if this can be done with a minimum of violence and of subsequent recriminations. Maybe a demoted patriarch can become a trustworthy company factor? Maybe former palace guards can patrol trade routes? Maybe suspicious natives can be shown that the newcomers are not despicable weaklings, profane profiteers or covert conquerors? Everybody happy? Not in real life - and not always in the Technic History, either.

Van Rijn opposes the cartelization of the Polesotechnic League. The League began by promoting liberty and can only change for the worse as successful companies grow into monopolies that merge with the state. Van Rijn's protege, David Falkayn, is an aristocrat who opposes revolutionary change on his home planet, Hermes, and who also addresses increasing interstellar economic inequities but eventually leaves human space to found a free society elsewhere.

Later, Dominic Flandry preserves legitimate rule in the Empire, then just the Empire, for as long as possible. After the Empire, Roan Tom and others do not rejoice in chaos but rebuild interstellar trade and alliances. Later again, humanity, having spread through several spiral arms of the galaxy, enters a new age of diversity and prosperity. I am not selling this history, just telling it like it is. The summary demonstrates that the narrative is a genuine history covering several successive periods.

There is a Time Patrol Timeline here.

Four imaginative Andersonian futures:

humanity evolves into the Danellians who found the Time Patrol which ensures the evolution of the Danellians;

League, Empire and later civilizations;

a relativistic spaceship survives into the next universe;

a time machine traverses circular time.