Two Unique Series

I have tried to convey that Poul Anderson's Technic History is special, even unique, for several reasons, one being its multiple presentations. Although the chronological linearity of Baen Books' The Technic Civilization Saga, is very welcome, it should not be allowed to obscure the original reading order:

first, we read four volumes containing eight installments about the Polesotechnic League, progressing from adventures of Nicholas van Rijn to the ultimate crisis in the League;

then we read a single novel set centuries later on the planet Avalon in the period of the early Terran Empire;

next, a substantial collection presented from an Avalonian perspective, beginning and ending with human-Ythrian interactions but also including eight more Polesotechnic League installments featuring our old friends, van Rijn, Falkayn, Adzel and the trader team as well as other, one-off, characters but also filling in crucial details and thus completing the history of the League.

For a decade and a half, Anderson's Time Patrol series was complete as a single volume collecting four stories arranged into a beginning, a middle and a culmination.  Then it became complete as two long volumes containing several longer, more complicated narratives whose reading order had to be revised as the series grew. Although Manse Everard remains present throughout, on several occasions he withdraws to the background as other, very different, characters come forward and even narrate their parts of the story. A second bigger culmination dwarfs the concluding story of the original collection. A time travel series with many well realized historical periods and subtle causality paradoxes has to be unique and in addition is enhanced by also reading Anderson's several one-off works on time travel.