The Festa de Sant Jordi isn't easy to explain. It's the feast day of Catalonia's patron saint, Saint George, when men would give their beloved a chivalrous rose. But it's also the anniversary of the death of two literary giants, Shakespeare and Cervantes, and in modern times, it became traditional for women to give a book in return. Books? Roses? Dragons? Lovers? Under a blue spring sky, with bookstalls lining Barcelona's grandest streets, and everyone, men and women, carrying roses and books for lovers and loved ones alike, it makes perfect sense. It's the most important date in the calendar for the city's publishing houses and booksellers, who bring best-selling authors from Spain and abroad to sign their latest works. And you can buy a long-stemmed rose (with a sprig of wheat, a symbol of fertility) on every corner, many sold to raise money for local causes.