Facts About Avalon Disclosed in The Earth Book Of Stormgate

(i) An Ythrian couple, Ferannian, an engineer, and Rennhi, a historian, "...held the country around Spearhead Lake." (Poul Anderson, The Earthbook Of Stormgate, New York, 1979, p. 1)

Despite participating in a technological society, the Ythrians are winged carnivores. Thus "...held the country..." means that they subsisted by flying, hunting and eating live prey.

(ii) They had regular contact with human beings because:

he worked in Centauri, Gray and other Avalonian towns;
travel routes crossed above Spearhead Lake;
there was a nearby copper mine;
they were "...guest-free..." (p. 1);
being near the large town of Gray, their choth, Stormgate, receives more human members than most. 

(iii) Rennhi wrote The Sky Book Of Stormgate about the ancestors on Ythri and the founders and descendants on Avalon and gathered material for the Earth Book, helped by her son, Hloch, but God stooped on her before she could write the second Book.

(iv) Hloch served in space during the Terran War and later visited Imperial planets in a merchant crew but then, tiring of the void, returned to the winds.

(v) Tariat, son of Lythran and Blawsa and Wyvan of Stormgate Choth, asked Hloch to complete the Earth Book, annals from the Discovery through the World-Taking but "...as told...by Terrans, who walk the earth." (p. 2)

(vi) Hloch begins to write on the peak of Mount Anrovil in the Weathermother...