The BBC's Who Do You Think You Are? stars comedian and actor David Walliams on Monday January 17. 

This week, Walliams, 50, will trace his family lineage and there are some huge discoveries along the way.

The show will air on BBC One and iPlayer at 9pm. 

The author and talent show judge learns of his paternal great-grandfather’s prolonged and traumatic experiences on the battlefields of the First World War.

His grandfather was committed to a lunatic asylum after his mental health deteriorated due to the war. 

Walliams also discovers his maternal great-great-grandfather, William Haines from Portsmouth, was blind as a result of invasive eye surgery.

He later became an entertainer, much like Walliams, starting off as a musician and travelling showman. 

He made his fortune running fairground attractions with the help of his wife and children.

“I love my great-great-grandfather’s story, it’s about resilience. I can’t help but be proud of him," Walliams said.