Taittinger champagne, Clarks shoes, Theakstons beer - three famous and successful family businesses that have passed down through the generations. So what prompted members of those families to leave the original firms and set up rival brands of their own? Producing champagne, making shoes and brewing beer. What's it like to compete with the companies they've known all their lives? And how easy is it to make their mark?

Paul Theakston, Founder and Chairman, Black Sheep Brewery

Virginie Taittinger, Founder, Virginie T

Galahad Clark, Founder and Managing Director, Vivobarefoot

Producer: Sally Abrahams.