The book is a collection of papers published by me in various journals and publications in the past three decades. They have been revised to include some new materials. The fifteen papers are studies on medieval economy with particular emphasis on Tamil country. The first three papers deal with the maritime activities of the Tamil people. The migration of Tamil traders to countries in Southeast Asia, Sri Lanka and Red sea areas has been projected. The studies include, the sea faring activities of the Pallavas, and the porcelain trade of the Chinese in the 13-17th centuries. The significant role played by medieval markets and the rise of Kanchipuram as an important market centre is highlighted. The activities of south Indian trade guilds, the development of craft workshops and production centres and also the technology of textile production are the other aspects studied. The last four papers deal with the monetary economy of the Tamil country, utilizing the literary, epigraphical and numismatic data. The papers have been thoroughly revised.