Palarandusk

Exceptionally ancient even for a Unknown , Paralandusk has been a forever-present good-natured and gentle protector of humanity with a whimsical sense of humor and fierce loyalty. He has been immortalized in uncountable family crests, artwork, tapestries, and tales over the history of men, elves and dwarves. He has a particular sympathy for the gnomes.

His history goes back even before the Netheril five thousand years ago. By all understanding of dragons, he should be long dead of old age, but whether he found powerful magics or has had his children take his name, he has persisted over all this time - directly intervening in threats of invasions, even from the Underdark. 

To his present title "The Unseen Protector" - he is essentially never seen any more or in any recent history, yet there remains enough of a threat that he may yet be watching and ready to act to give wise enemies pause in striking against the Sword Coast.

(See also: https://forgottenrealms.fandom.com/wiki/Palarandusk)