When, four years ago, Stockport-based family brewer Frederic Robinson announced it was going to brew beer with rock legends Iron Maiden, some observers might have dismissed it as a marketing gimmick. But that’s not possible any longer. Trooper, a 4.7% abv ale inspired by a song about the Charge of the Light Brigade, is now Robinson’s best selling beer. A total of 15 million pints have been sunk. The brand is sold nationwide in pubs and supermarkets, and in 55 countries around the world.