Originally published in 1930, this book presents an English translation of the 1639 journal of Dutch naval commander Maarten Harpertszoon Tromp (1598-1653), who led the Dutch fleet in a decisive victory over the Spanish at the Battle of the Downs during that year. Translation of the journal was carried out by Charles Ralph Boxer (1904-2000), a renowned specialist in Dutch and Portugese naval history and the early colonial expansion of European nations. Created in response to 'an increasing interest shown by English historians in naval matters', the text provides both an insight into Dutch naval strategy and a revealing portrait of Tromp's character. A highly detailed introduction, illustrative figures and a bibliography are included. This book will be of value to anyone with an interest in European and Maritime history.