Early Contacts With Important Planets

Ythri, Gray/Avalon and Merseia are all discovered during the Grand Survey. We see:

Ythri discovered by a Survey spaceship;
Gray later explored by space faring Ythrians employing human beings;
Merseia helped by the Polesotechnic League.

All three planets later play major roles. Even before the discovery of Ythri, Cynthia and Woden had been discovered and explored and Hermes had been colonized. Before the exploration of Gray, Dido had been discovered and its sister planet Aeneas colonized. We know this because the human explorers of Gray include an Aenean who was employed because of contacts he made with Ythrians at the University of Nova Roma on Aeneas.

The first two short stories in The Earth Book Of Stormgate directly or indirectly introduce seven significant planets, those mentioned minus Merseia. We meet a Wodenite in the very next short story.

David Falkayn leaves three legacies to the Terran Empire and to later civilizations. He rescued Merseia, discovered Mirkheim and colonized Avalon.