The new season of Who Do You Think You Are? premieres Monday, May 21 at 9/8c only on TLC.

Actress Liv Tyler discovers a musician in her line of ancestors.

Get a first look at actress Liv Tyler’s journey.

Actor John Stamos meets with modern Greek historian Katerina Lagos where he learns that his paternal grandfather is listed as an orphan at only age 13.

Actor John Stamos discovers his paternal great-grandfather was murdered in a village in Greece.

Get a first look as actor John Stamos digs into his family history.

Smokey Robinson continues to learn about the surprising path of his maternal grandfather.

Get a first look at Smokey Robinson’s journey of exploring his family history.

First look at Jessica Biel’s journey of learning about her ancestry.

Noah Wyle learns the truth about the demise of his ancestor.

Noah Wyle discovers his ancestor fought in the Battle of Shiloh, one of the bloodiest battles of the Civil War.

A first look at actor Noah Wyle's journey to learn more about his family history.

Jennifer Grey’s ancestors travel to the U.S.

Jennifer Grey discovers her grandfather was a conscientious objector.

Jennifer Grey explains how she remembers her grandfather

Get a first look at Jennifer Grey’s journey on Who Do You Think You Are?

Chris Noth tracks down family torn apart by a devastating disaster when he follows his relative's trail from Spain to Ireland and finds a man who endured oppression, but rose up to fight in one of the fiercest battles of all time to become a war hero.

Actress Liv Tyler discovers a musician in her line of ancestors.

Sean Hayes tours the Irish prison where his great-grandfather spent time. To call it bleak is an understatement.

The new season of Who Do You Think You Are? premieres Monday, May 21 at 9/8c only on TLC.

Lea Michele unravels secrets of her Jewish roots, discovering a great-grandmother lost without a country; relatives fighting to be together; ancestors suffering devastating loss; and long lost family reuniting after decades of separation.

Sean Hayes learns the problems his great-grandfather faced and why he was desperate to leave Ireland.

Lea Michele unravels secrets of her Jewish roots, discovering a great-grandmother lost without a country.

Sean Hayes consults an old newspaper to learn more about the assault accusations between Patrick Hayes Senior and Patrick Junior.

Beyond a family of Hollywood legends, actor/director Tony Goldwyn explores his maternal lineage. He is introduced to a heritage of political activism; a couple ahead of their time proudly fighting for abolition, women's rights and westward expansion.

Tony Goldwyn's 3 times great-grandmother traveled from New York to Oregon by crossing through Panama. Watch as he learns more about her journey.

Tony Goldwyn's 3 times great-grandparents were political activists behind the Seduction Act. He learns why this legislation was so important to them.

America Ferrera and her sister look at old family photos and share memories of their dad, who left when she was just eight.

America Ferrera learns that her great-grandfather was involved in a revolt against the president he helped put in office.

America Ferrera searches for a connection to a father she barely knew, and discovers a great grandfather who led multiple revolts against the government and left an enduring mark on Honduran history.

Actor/Director Bill Paxton researches his paternal lineage, uncovering the captivating life of an ancestor who was a war hero in an historic battle and who shaped politics and society during a turbulent era.

As Bill Paxton uncovers facts about his ancestor's role in the American Revolution, he also learns a surprising history lesson.