David Walliams learns of his great-grandfather’s traumatic experiences during the First World War, which condemned him to a lifetime in what was then called a lunatic asylum.

Silent Witness actor Liz Carr gets forensic about her family history, discovering that her great-great-great-grandfather was involved in an attempted murder in rural Northern Ireland in the 1850s.

Actor Ruth Jones - Nessa from Gavin and Stacey - uncovers her grandfather's role in the Medical Aid Societies of south Wales, which provided a model for the NHS.

Doctor Who actor Jodie Whittaker finds out how her great-great-grandfather worked his way up from child labourer in a Yorkshire coal mine to mine owner.