In the 19th century, Britain imagined itself as a bastion of beef-eating carnivores. But at a time when meat consumption was taken as a signifier of personal heartiness and national prosperity, a rebel alliance formed – a ragtag group of religious devotees, health enthusiasts, temperance campaigners, animal rights activists, political reformers and eccentrics. They were all united by one cause: vegetarianism. Dr James Gregory tells Ellie Cawthorne about how going meat-free became an organised movement in Victorian Britain.