Britain's overseas Empire pre-eminently involved the sea. In a two-way process, ships carried travellers and explorers, trade goods, migrants to new lands, soldiers to fight wars and garrison colonies, and also ideas and plants that would find fertile minds and soils in other lands. These essays, deriving from a National Maritime Museum (London) conference, provide a wide-ranging and comprehensive picture of the activities of maritime empire. They discuss a variety of issues: maritime trades, among them the trans-Atlantic slave trade, Honduran mahogany for shipping to Britain, the movement of horses across the vast reaches of Asia and the Indian Ocean; the impact of new technologies as Empire expanded in the nineteenth century; the sailors who manned the ships, the settlers who moved overseas, and the major ports of the Imperial world; plus the role of the navy in hydrographic survey.