Fifty years ago, Yves Saint Laurent visited Marrakech and fell head over heels for its Majorelle gardens. As a new YSL museum opens in the city, Tristan Rutherford tells a love story half a century in the making. It's 1966 and all that. In London, a man boots a football into the back of a net and wins his team the World Cup. In Milan, an unknown designer named Giorgio Armani starts a couture business. And, in Paris, something else extraordinary happens.