Saunders Lewis

A founder of Plaid Cymru in 1925 and a major Welsh-language dramatist, Lewis was jailed in 1936 for setting fire to an RAF bombing school at Penyberth on the Llŷn peninsula. His 1962 radio lecture Tynged yr Iaith, 'The Fate of the Language', warned that Welsh would die without direct action, and directly inspired the founding of Cymdeithas yr Iaith Gymraeg, the Welsh Language Society, whose campaigns for bilingual signs and services changed public life. He argued the language mattered more than self-government.