Lisa Kudrow uncovers a long line of Sheen family rebels When the third season of "Who Do You Think You Are?" premieres Friday, executive producer Lisa Kudrow says there's likely to be some real surprises coming about the relatives and ancestors of 12 celebrities -- including former "West Wing" star Martin Sheen. As the series traces the roots of famous names, the celebrities themselves head back to their relatives' countries of origin (when possible). And as Kudrow told the TODAY team on the Plaza on Thursday, Sheen is a mix of Irish and Spanish backgrounds. "We know Martin Sheen is sort of an activist -- not sort of -- and he's been in jail a few times over his protests," said Kudrow. And in Ireland he finds that his mother's brother spent time in jail, but for the civil war. And then he goes to Spain, and finds his father's brother -- he didn't know this -- also spent a lot of time in jail because he was involved in fighting (Fascist dictator Francisco) Franco in the very beginning. This may explain a lot about Martin's son, Charlie Sheen. Rebels run in the family. Want to take a peek into the secret histories of other celebrities? Tune in to "Who Do You Think You Are?" Friday night at 8:00 p.m. Will you tune in? Have you researched your own genealogical history?