Prince Henry of Prussia was the second son of Crown Prince Frederick William, later Emperor Frederick III, and the Crown Princess, later Empress Frederick. As a youth he joined the imperial German navy, and travelled widely throughout Asia and the Americas. An easygoing character, renowned for his interest in motoring and aviation as well as nautical matters, he was much more popular with his royal and imperial cousins throughout Europe than his elder brother, Emperor William II. Yet his love of England, and reluctance to contemplate the possibility of hostilities between Germany and England, is thought to have led to his convincing the Emperor that the English would remain neutral as the likelihood of war became increasingly inevitable in 1914. This is the first biography in English of an often-overlooked prince.