Double Diamond is the story of Umbro, an ever-present figure in the development of modern football and the multi-billion-pound sportswear industry. From Sir Geoff Hurst's World Cup Final hat-trick to Sergio Agüero's 2012 injury-time Premier League-winning strike, Umbro has featured in more iconic footballing moments than any other brand. Football writer, kit collector and university academic Alex Ireland charts the Manchester sportswear firm's 100-year existence, from its 1924 foundation in a Cheshire pub backroom to clothing 85 per cent of British clubs and half the World Cup finals teams by 1966. You'll discover the central role Umbro has played in the evolution of sportswear, the firm being a leader in the application of new technologies and innovations. From the invention of the replica kit in 1959 to supplying 11 teams in the inaugural 1992/93 Premier League season, Umbro has remained a key player amid the growing commercialisation and globalisation of the beautiful game.