From the Greek professional armies of Alexander, through the Hundred Years War, indeed, to today, mercenaries have been ever-present, their role constantly evolving. In this compelling new history William Urban takes up their captivating and turbulent story from 1550 to 1763. The 16th century saw the beginning of a revolution in military technology and strategy. Political and economic systems were radically evolving, too. Mercenaries are often considered a marginal phenomenon, but Urban shows that they were integral to these developments. Increasingly not just individual soldiers and officers became mercenaries, but entire armies of well-equipped, well-trained, and, in time, experienced soldiers were available to friends and allies. By the late-1600s these armies had evolved into large and efficient fighting forces. By the mid-1700s military service had become a profession. The old-fashioned mercenary was less common, but he would not disappear until swept away by the volunteer armies of the French Revolution.