For most of its modern history, India was fated to be on the receiving end of cultural influence from other civilisations. But this isn't the complete story. A full millennium earlier, India's major cultural exports - religion, art, technology, astronomy, mathematics, medicine, language and literature - were shaping civilisations, traveling as far as Afghanistan in the West and Japan in the East.

Out of India came pioneering merchants, astronomers and astrologers, scientists and ma...