Volkihar Master Vampire

Volkihar Master Vampires are the highest level Vampires encountered in Skyrim. Like all Vampires, you can contract Sanguinare Vampiris from their attacks. They are extremely deadly, casting Destruction spells and Vampiric Drain which can sap large amounts of health. They generally use Ice Spike when encountered at higher levels, and Frostbite at lower levels. They are usually accompanied by 1 or 2 Volkihar Vampires, as Volkihar Master Vampires are leaders of the Volkihar Vampire Group.

Location
A Volkihar Master Vampire can also be found in Bloodlet Throne under the quest "Find the copy of Remanada". He is a highly difficult opponent and can leech life in large amounts. One tactic is to lure him to the bridge outside his cave and use Unrelenting Force to blow him down. He will still not die but his health is reduced considerably.

A Volkihar Master Vampire can be found at Shriekwind Bastion. Another method is to use the pull-chain right outside of his cave to trap him inside, enabling you to slowly get his health down with the option to withdraw and heal yourself.

With high enough (80+) skills in sneak and archery, the Shriekwind Bastion's master vampire can easily be killed by fist muffling, opening the door to its cave (the one after the flame traps). It will be directly in front of you, but if you're crouching it won't react at first and you can quickly dispatch it with arrows (high level archery recommended). Since you're sneaking it will have a hard time detecting you, even after the first arrow, giving you time to kill it before it locates you.