Multiple Narratives

Poul Anderson's History of Technic Civilization presents multiple narratives:

the history of the Solar Commonwealth and the Polesotechnic League and the later history of the Terran Empire overlap with the history presented in The Earth Book Of Stormgate;

from within the Empire, Axor's quest for the Universal Incarnation converges with the longer history of the Ancients;

millennia after the Empire, human civilizations spread through several spiral arms of the galaxy;

at a much later date, a Galactic Archaeological Society refers back to "the First Empire" so how many have there been?;

cosmic events affect interstellar civilizations, e.g., the supernova that created Mirkheim, the paths of several rogue planets, the eccentrically orbiting "Cloud Universe";

we do not learn the later histories of the non-human intelligent species influenced by Technic civilization, e.g.:

some, though not all, Cynthian trade routes gain spacefaring technology;

most Wodenites continue to bound across their plains although a few gain scholarships to study off-planet;

the rescued but resentful and embittered Merseians build a rival empire but do not gain control of the galaxy and some members of their species settle peacefully on a human colony planet.

This is more than just League, then Empire.