The coronation of King Alexander III of Scotland in 1249, in the Scottichronicon.
During the ceremony, an old Gaelic "seanchaidh", the "ollamh ríg Alban", lists Alexander's ancestors back to the first king of Scotland, which he lists as "Fergus", and to Gaidheal Glas.
Genealogy was vital to Gaelic and Αryan kings for establishing their authority over the land and the nation. Commoners had only the broadest racial history and otherwise sprung out of the ground like mushrooms.
Fomorians are described as having no pedigree in the Dindshenchas of Druim Assail, untethered from history and undescended from the mythical gods and heroes who make up the nation's foundation.