In the Middle Assyrian period (14th-11th centuries), the kings of Assur undertook to constitute a vast territorial state, one of the frontier zones of which was the middle Euphrates. For a long time the only excavated site dating to this period was Tell Hariri, ancient Mari, where A. Parrot had identified a strong Assyrian presence. Today in the light of the excavations at Haditha, the situation is much more complex. Subjugated to the Babylonian, then to the Assyrian kings, the middle Euphrates valley found itself at the permanent point of contact between these two states, as is clear from the texts and the material culture. From the 11th century onwards more and more frequent and reckless Aramaean incursions forced the Assyrian kings to fortify the region. This network of fortresses, known from excavations and surveys, was intended to protect its southern border as well as to control the important commercial route that linked Mesopotamia to the Palmyrene area, the Levant and Egypt. Due to its situation on the border and its occupation of a military or commercial character, the region was probably very poorly integrated into the administrative system that is developed and now well known in the Jezira area further north. This would explain the apparent rarity of Middle Assyrian material much better than a lack of control of the kings of Assur.