20 Things You Didn't Know About Star Trek: First Contact
16. Zefram Cochrane Is Greeted By Spock's Great-Grandfather
The Vulcan captain of the T'Plana-Hath who crucially greets Zefram Cochrane and initiates first contact is never named in the movie itself or its end credits, though it's stated in a Star Trek card game and also a reference book that this is in fact Solkar, Spock's (Leonard Nimoy) great-grandfather.
We first hear mention of Solkar way back in Star Trek III: The Search for Spock, where he's named as the father of Skon and grandfather of Sarek, Spock's own father.
Fan service of this sort is tricky and often ends up confusing or enraging fans, but in this case it's a meaningful addition that's just subtle enough to pass by more casual observers.