When Augustus (r. 27 BC-AD 14) came to the throne as the first emperor of Rome, he began to bring order to the chaos that almost 20 years of civil war had wrought. Areas that had been added piecemeal to the Roman Republic, from Spain and Gaul to Dalmatia, needed to be restructured as provinces of the empire, while in the East, Augustus reorganised Asia Minor and Syria, and held the Parthian empire in check with cunning diplomacy. The foundations of the empire were thus laid by Augustus, and his aspirations for world conquest were passed on to his successors, who would strive to defend, expand and consolidate the empire after his death. Under Trajan (AD 98-117) the empire reached its largest extent - some 6.5 million square kilometres. Its presence in much of present-day Western and Central Europe gave the area a lasting legacy in a range of areas, from legal matters to languages and from architecture to religious belief.In this book ancient-warfare specialist Duncan Campbell explores the course of the wars that ensued as successive emperors sought to extend the empire, from Claudius' conquest of Britannia (AD 43) and Domitian's campaigns on the Rhine (AD 83) and the Danube (AD 89, 92), through Trajan's Dacian Wars (AD 101-03, 105-06) and Parthian War (AD 117), to Marcus Aurelius' Marcomannic Wars (AD 167-75, 177-80), as well as the Jewish Wars (AD 66-74 and AD 132-36). The period covered in this book ends with the consolidation of the Roman frontiers along the Rhine and Danube - 'this far and no further' - and uneasy peace with the Parthian empire, wracked by its own internal troubles. The murder of the emperor Pertinax in AD 193 was to usher in a period of instability and civil war, dominated by the mighty Septimius Severus (r. AD 193-212).This book provides a summary of the strengths, limitations and evolving character of the Roman army during the first two centuries AD, as well as those of the forces of Rome's enemies across the Rhine and Danube in Germany and Romania, and in the East, in the form of the Parthian empire of Iraq/Iran. The characters and achievements of the soldiers and civilians who fought Rome's enemies and administered the new provinces carved out in war are brought to life in vivid detail. Fully illustrated with photographs depicting the emperors, their armies and enemies, and the remains of Roman fortifications and public buildings, plus informative full-colour maps, this is the epic story of the wars waged by a succession of emperors during the period in which Imperial Rome reached its zenith.