The Straits of Malacca, today one of the busiest stretches of sea in the world, extend for some 500 miles from north to south between Malaysia and the Indonesian island of Sumatra, and its waters are shared between three states: Malaysia, Singapore and Indonesia. The Straits are narrow and crowded: at their widest they are only 126 nautical miles around the island of Penang; whilst at their narrowest, at Little Karimun, close to the adjoining Straits of Singapore, they are little more than nine nautical miles. This stretch of water, shallow, littered with sandbanks and divided up by islands large and small, together with the coastal territories, estuaries, and human settlements that abut it, has been enormously important in shaping the historical and contemporary patterns of life and livelihood in Southeast Asia. The way in which these waters, and the traffic —human, biotic and marine-upon it, have shaped this important region is the subject of this book.