Four Significant Characters

In his Editor's Introduction to the fourth NESFA collection, Rick Katze writes that Manse Everard, David Falkayn and Nicholas van Rijn are in this volume and that Dominic Flandry will also be in the fifth. These are Poul Anderson's four most significant characters. Every dedicated Anderson fan has already read everything that there is to be read about each of the four. Anderson also has many comparable characters in other series and in single works.

Between them, the four named characters represent three institutions:

the Time Patrol, founded by Danellians and staffed by human beings;
the Polesotechnic League and the Terran Empire, founded by human beings and incorporating other species.

Van Rijn and Falkayn live in the same period;
Flandry lives in a later period of the same history;
Everard lives in a different kind of history.

Everard's timeline is single and mutable, hence the need for a Time Patrol, whereas the timelines connected to the Old Phoenix Inn are many and static with no direct contact. Thus, we read seven omnibus volumes of the Technic History with no reference to the Old Phoenix but do find van Rijn in the Inn elsewhere in the Anderson canon. Thus also, Anderson imagined both a Time Patrol universe and an Old Phoenix multiverse.