There was a vague but increasing knowledge of the complex civilisations in China and India, from which luxury goods (notably cotton and silk textiles as well as ceramics) were imported. Although the Crusades produced relatively little in the way of scholarly interchange, the eruption of the Mongol Empire had strategic implications for both the Crusader kingdoms and Europe itself, and led to extended diplomatic contacts. From the Age of Exploration, European interest in mapping Asia, and especially the sea-routes, became intense, though mostly pursued outside the universities.