The word dimatu appears in cuneiform texts of the second millennium BC. Five different meanings have been proposed for the word - type of structure, kind of settlement, administrative district, taxation unit and extended family commune. This study aims to reassess the available textual evidence to present a new interpretation of the meaning of dimatu . The author concludes that the word has both administrative and architectural meanings. The first part of the volume considers cuneiform texts from the regions of Mesopotamia, Syria, and Elam with a particular focus on the kingdom of Arraphe. The second part presents archaeological evidence from northern Mesopotamia. The author looks at the excavation of Tell Fahar, which is the only site to have ever been identified through textual evidence as a dimatu, and discusses survey methodology as a means to identifying dimatu settlements. The third part discusses the origin of dimatu and considers the role dimatu played in the economy and administration of Greater Mesopotamia in the second millennium BC. Nine appendices list the sources of evidence.