The year 135 BC saw the outbreak of the so-called ‘First Servile War’, which proved to be just the first of a series of conflicts that ravaged the Roman Republic during the following century and changed forever the institutions of the Roman state. This bloody and violent period of civil wars and recurrent slave revolts (most famously that of Spartacus) saw the ascendancy of many famous generals who obtained great military victories, including: Marius, Sulla, Crassus, Pompey, Julius Caesar, Mark Antony and Octavian. They fought for complete dominance over Rome but, at the same time, conducted a series of imperialist campaigns that greatly expanded the territorial extension of the Roman Republic. In discussing these campaigns of conquest, the author shows how they were strongly linked with the civil conflicts and how the events that started in 135 BC progressively led to the birth of the Roman Empire under Octavian (Augustus). The author also describes the only civil war taking place during the Early Empire, i.e. that of AD 69 (‘The Year of the Four Emperors’) before providing a detailed description of the organization and equipment of the varied military forces that took part in the Roman civil wars during this crucial period, outlining crucial developments across the period. As usual for the Armies of the Past series, there are dozens of colour photos depicting replica arms, armour and dress in use.