LOS ANGELES (Reuters Life!) - Think you know all about celebrities? Think again. Some of them barely know their own family history.
But seven of America's leading stars of movies, television and sports share their journeys into their pasts in NBC's new TV series "Who Do You Think You Are?", starting on Friday.
The show takes former "Friends" star Lisa Kudrow back to the World War Two pogroms -- destruction and killing -- in Belarus; "Sex and the City" actress Sarah Jessica Parker discovers ancestors from the California gold rush; and African American director Spike Lee finds he may have more Caucasian blood than he thought.
"I've always known who I am, but I think I now know myself more," Lee says of his family connections to slavery in the United States.
Actresses Brooke Shields and Susan Sarandon, actor Matthew Broderick and Hall of Fame footballer Emmitt Smith are also featured.
Part documentary and part historical accounting, the series takes viewers and the stars back to events like the Salem witch trials and the immigrant slums of 19th century New York.
It is already being dubbed by some critics as the potential "Roots" of the 21st century -- a reference to the Emmy-winning 1977 TV drama series about African-American slavery.
Those profiled in "Who Do You Think You Are" are mostly friends of executive producers Kudrow and actor Dan Bucatinsky, who were approached with the idea of taking part in a U.S. version of the popular British TV series of the same name.
Research is done by genealogists and historians, and with the help of popular web site ancestry.com. But the celebrities know little in advance of where their personal journey will take them, both physically and emotionally.
"Everyone was nervous to go on the journey...They (the producers) are learning as they're going along. They wouldn't even tell us -- they would say we need your passport because we need to get a visa, " Kudrow said.
"They would also say, you'll need clothes for winter weather for three days, and then it will be warm weather...So they really help you prepare but they don't give you any information," she said.
Shields' journey goes back to 17th century French royalty. But some others hit brick walls where the trail runs out earlier along the road.
"With African American stories, there's that barrier of slavery where there are just no records a lot of the time. And then also for Jews who came from very small shtetls, there are no records because the synagogues were all burned down by the Nazis," Kudrow said.
Although the initial spotlight is on celebrities, ordinary people, and America's rich history, are the real stars.
"While the person who is taking the audience on this journey is well known, their great-great grandfather was not famous. The people that we're focusing on in these stories are ordinary people," Kudrow said.
Editing by Bob Tourtellotte