The Alamanni were a Germanic people that figure prominently in the history of the later Empire. Despite their high profile, there has been surprisingly little written on them in English. This study ...aims to fill the gap. Drawing on the latest literary, historical, and archaeological research, it seeks to establish the origins of the Alamanni, the pattern and character of their settlement, the main features of their society, and the nature and significance of their relationship with Rome. It centres on the mid-4th century, recorded in detail by a variety of sources including Ammianus Marcellinus and the emperor Julian. It argues that, like the other western Germani encountered by Rome from the 1st century BC, the Alamanni were economically, socially, and politically far too weak to endanger the Empire. However, Roman rulers conjured up a ‘Germanic threat’, and exploited it for their own political ends. Rather than constantly imperilling the Empire's existence, the Alamanni became too closely linked to its fortunes. It was for this reason, in particular Roman restriction of their ability to unite under strong leaders, that unlike their long-standing neighbours the Burgundians and Franks, the Alamanni failed to establish a post-Roman successor kingdom in the 5th century.