Cadolyn ruled over Kaylonna, the fertile sub-continent. Cadolyn was renowned as an idle and slothful dragon who never did anything for himself. Cadolyn was said to be the most beautiful of the elder dragons and this story is confirmed by the fact the only Cadolyn ever mated with the three female elder dragons. Cadolyn encouraged his offspring to ravage Kaylonna in his place while he stayed in his lair. Cadolyn died sometime during the Second Age. He was the eighth of the dragons to die.
Ultimately, Cadolyn is responsible for the creation of all the lesser dragons known today.