Despite a reduced population, perennial war, endemic piracy, shortage of bullion, recurring plague, sporadic famine, deteriorating climatic conditions and little or no encouragement from the crown, the English shipping industry not only survived, but in certain sectors prospered, in the hundred years between c.1350 and c.1450. During that period there was a marked change in the pattern of goods imported and exported, an increasing sophistication in the management of shipping, and an awakening interest in ship-ownership for both mercantile expansion and for capital investment. At the centre of the shipping industry was the shipmaster on whose ship-handling and commercial skills the viability of every overseas enterprise depended. To be successful, a shipmaster, necessarily endowed with the initiative, courage and physical strength to overcome the inherent risica maris et gentium of his profession, also had to have an extensive array of non-physical skills. Alone, in partnership or as an employee, he had to negotiate for cargoes at profitable freight rates, victual and maintain his ship, recruit and manage his crew, and navigate in all weathers through unmarked seas. This wide range of skills was mediated by a protean system of laws, contradictory political policies, a paucity of navigational instruments and unreliable equipment. Although there has been much research on English seaborne trade and commercial organisation in the late Middle Ages – encompassing the economic, legal, political and social dimensions of the subject – there has been no thorough or consolidated examination of the work of the medieval shipmaster.