Travel always spreads disease. Bubonic plague reached Turkey in 1347 via the Silk Road, following an outbreak in 1330s China. By 1348, it raged in Italy, shadowing the gaiety of Boccaccio's Decameron. By 1351, half of Europe lay in plague pits. One hundred and fifty years later, the conquistadors took smallpox to the Americas, decimating local populations. They returned - many believe - with syphilis, which 'enjoyed' its first European outbreak in 1495 among Charles VIII's army, then besieging Naples. The French called it the 'Neapolitan disease' and carried it home. In England, it became the 'French pox' and in Tahiti, the 'British disease', imported by the Royal Navy.