Hloch And Saxo

Tariat, Wyvan of Stormgate Choth on Avalon, asked Hloch to compile The Earth Book Of Stormgate, which is a major part of Volumes I-III of Poul Anderson's History of Technic Civilization. Archbishop Absalon asked Saxo to write Gesta Danorum, which is the only source for Anderson's War Of The Gods.

To compare some legendary, historical and fictional dates -

Grallon, former King of Ys, became Duke of Armorica in 407.

Grallon's successor, King Salaun, reigned 421-435.

The source of the Arthurian legend was in the mid-400's, 450-455. See combox here.

The reign of the last Western Roman Emperor ended in 476. See here.

"Saxo places Hadding three generations before Hrolf Kraki."
-War Of The Gods (New York, 1999), p. 301.

Anderson dates Hrolf Kraki twenty or thirty years after 512-520.
-Hrolf Kraki's Saga (New York, 1973), p. xviii.