Captain Tremouille is one of the first people you meet at Vulkhel Guard.
He is the captain of the ship that rescued you after you reappeared in Tamriel if you follow Aldmeri Dominion faction. He also points you in the direction of Khenarthi's Roost where you will find Razum-dar and your early questing. To get over there, he suggests looking of Sugar-Claws down on the dock. In all, he starts you on the Storm on the Horizon questline.
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