Spock's Vulcan grandfather is named Skon, and his grandfather named Solkar, in Search for Spock. I think I read somewhere that one of them is namedropped once of twice during Enterprise, but never seen.
Solkar is said to be the first Vulcan ambassador to Earth. "The Catwalk" was the episode in question.
(Also, I can't remember where I read this, but I *think* Solkar is also supposed to be the captain of the T'plana'hath seen in ST:FC. )