This detailed survey of the archaeological evidence reassesses the Middle Assyrian period, when the first Assyrian empire can be said to have been founded as a result of large scale military expansion. The chronology of expansion is reviewed in the light of recent results from excavations, and a more nuanced view of the empire's preceived decline in the 12th century BC. Tenu also examines the organisation and administration of the empire and the integration of non-Assyrian provinces and populations, as well as the organisation of the Assyrian military. French text.