Although historical texts differ on the exact timeline of the elves

An alternate theory proposed in the Book of Folklore links the creation and ‘life-force’ of Gielinor with the existence of an ancient race of creatures known as the Elder-dragons. As long as the Elder-dragons remained, the world would continue, though the extinction of the aforementioned Dragons would result in the “end of the world.” It is possible that the Elder-dragons could be the Dragonkin that Robert the Strong annihilated; however, the survival of a very limited number would tie in with the Elder-dragons and the world’s continued existence. It is also possible that fairy dragons, such as K’klik, were these Elder-dragons, as his examine text asks the question, ‘Could this be one of the elder dragons?’
The Elder-dragon theory is not widely known, nor popular with skeptics, believing it to have been created to throw doubt on the idea of Gielinor being barren before the gods arrived.

Although historical texts differ on the exact timeline of the elves, many scholars believe the elves arrived some time in the First Age through the World Gate. The elves, who had come from another world, were led through the gate by Seren, who brought them into Tirannwn.

Once there, Seren brought the elves to a massive clearing in the forest of Isafdar, where she had created the legendary Tower of Voices from Crystal. Here the elves constructed Prifddinas, one of Gielinor’s first cities and the oldest settlement still in existence today.