Valendrian is the Elder of the Denerim Alienage - A representative of sorts. He appears in the City Elf Origin, as well as at the end of the quest Unrest in the Alienage during the Landsmeet portion of the game.
See Also: Codex Entry:Valendrian
Background
Valendrian effectively runs the Alienage. He acts as the voice of the Alienage, although lacks any really power in Denerim politics He is a good friend of Duncan, whom he respects for recognising that 'talent can be found anywhere - not just among nobles'.
Involved In
He acts as the priest during Soris and the Male City Elf Warden's wedding, before it is crashed by Vaughan. He is initially submissive, but then backs the City Elf's plan to attack the Arl Of Denerim's Estate to free the kidnapped women.
He later appears as a captive of Caladrius, to a non city-elf Warden player, should the player decide to release the captive elves. If the player is a city elf, Valendrian will have already been shipped off to Tevinter, and Cyrion will be there in his place.