This thesis provides a general survey of the excavations which have taken place at the Old Babylonian sites in the Diyala region (east Tigris) and of 145 unpublished tablets from Me-Turan (Tell al-Sib and Tell Haddad) in the Middle Diyala region, which lies about 18 km to the west of Jalawlah, west of the Diyala river. The site which produced the tablets published herein is located in the fertile agricultural region near the mouth of the Narin river where it flows into the Diyala river. It was one of the main centres of the plain in the second millennium B.C. on the trade routes linking south and north Mesopotamia and southern Iran. It was surrounded by a thick wall (mentioned in an Ishchali text referring to Ipiq-Adad II, king of Eshnunna). It was discovered by the State Organization of Antiquities and Heritage that the high wall enclosed Me-Turan, Therefore, it is fairly safe to state that Me-Turan was probably the administrative centre of an agricultural district in the Old Babylonian period. Over 750 Old Babylonian tablets as well as fragments were found during the first and second seasons, and the excavations still continue. Damage of the tell was caused by recent agricultural activities. The third level proved to be of great importance. A street was discovered between Tell al-Sib and Tell Haddad, and the structures occupied both mounds. However, there is no doubt that Me-Turan and other towns in the Middle Diyala region were part of the Eshnunna kingdom (1900-1700). We have proof that the rulers of Eshnunna, Sin-abushu, Ipiq-Adad II, Dadusha, Ibal-pi-EL II, Silli-Sin and Iluni, exerted control, though temporarily over Me-Turan, since the oath and date formulas appropriate to them are found in the texts. Further evidence shows that the site is that of Me-Turan; inscribed bricks from the paving of the courtyard of a temple were re-used for the Assyrian level of Tell Haddad, This temple was rebuilt by Assur-banipal. Our tablets deal with administrative and economic matters, including lists of names, field purchases, letters and one adoption contract. The texts reveal that in Me-Turan there were many large grain stores for barley, wheat, and sesame, some of the stores being for consumption, and others for providing next year's produce, Makkur-Nanna, Eribam, Balilum and Belanum, the officials who were responsible for expenditures and received the various kinds of grain, were under the order of Eshnunna rulers. We read about Amorites and their tribes; Amnanum, Idamaraz, Yabasa, Yahrurum, and Yamutbal, as well as other Semitic peoples who had penetrated into the Middle Diyala region from the west in the course of the second millennium B.C. There was a connection between Me-Turan and other cities or towns inside and outside of the Middle Diyala region, as, for instance, with Agsiya, Arkum, Arrapha, Assur, Babylon, Batir, Der, Elam, Habab, Karash, Kullan, Lashamar, Namar, SAHAR, Sanipa, SIPA, Tirga, Zabban and Zubrila. All in all, our archaeological and literary evidence provides us with new data in relation to the social, economic and administrative areas. The evidence confirms that Old Babylonian life in our area was in almost every respect typical of life in other parts of Babylonia.