Indians of old were keenly alive to the expansion of dominions, acquisition of wealth, and the development of trade, industry and commerce. The material prosperity they gained in these various ways was reflected in the luxury and elegance that characterized the society... The adventurous spirit of the Indians carried them even as far as the North Sea, while their caravans traveled from one end of Asia to the other.

R. C. Majumdar, Ancient India, 1977, p. 210-216.