a tributary of the Tigris River that catches its water from the Zagros Mountains northeast of Baghdad. After it escapes from the mountains, the Diyala crosses two plains: a triangular basin northeast of a low row of promontories, Jebel Hamrin, and the alluvium surrounding the river south of the Hamrin before it joins the Tigris at Baghdad. The Diyala region is traditionally divided into three zones: the Upper Diyala, referring to the course of the river through the mountainous Zagros; the Middle Diyala, which includes the Hamrin basin and immediate catchment areas; and the Lower Diyala, the areas southwest of the Hamrin range.

The Diyala River traverses the central western Zagros Mountains and the northeastern part of the Mesopotamian alluvium. One of the oldest known trade routes, the Silk Road, is located in this region. Connecting the Mediterranean with China, the route is also called the Great Khorasan Road between Baghdad and Kermanshah. The route follows the Diyala River up from Baghdad through the Hamrin, where it crosses to the Iranian plateau through passes in the Zagros Mountains. These geographic details are important in reconstructing ancient human exploitation of the region.

In archaeological terms, the Diyala traditionally refers to the Lower Diyala region and includes the countryside receiving water from the Diyala River by irrigation canals. Recent archaeological results from the Hamrin make it plausible to include this region as well. The Lower Diyala region has been identified at the province of Eshnunna, an important city-state during the Isin-Larsa period. Eshnunna is modern Tell Asmar. Other important sites have also been identified, such as Khafajeh as the ancient town of Tutub.

The first systematic archaeological investigation of the Lower Diyala plain took place from 1930 to 1938 with the Iraq Expedition, directed by Henri Frankfort. It was the first large-scale expedition from the Oriental Institute of the University of Chicago to Iraq. Among others, the staff also included Thorkild Jacobsen as epigrapher, Seton Lloyd, Gordon Loud, and Pinhas Delougaz. One reason for choosing the Diyala region was the increasing number of clay tablets and art objects being brought to the antiquities market in Baghdad from illicit digging into the mounds in the area. It was also assumed that the region was historically important and that Tell Asmar was indeed the ancient city of Eshnunna. The Oriental Institute expedition concentrated on the excavations of four sites: Khafajeh, Tell Asmar, Tell Agrab, and Ishchali. It built its expedition house at Tell Asmar. [See the biographies of Frankfort, Jacobsen, and Lloyd.]

Extensive surveys of the Lower Diyala plain combined with excavations were carried out In 1957–1958 by Thorkild Jacobsen, Robert McCormick Adams, and Fuad Safar under the Diyala Basin Archaeological Project. [See the biography of Safar.] The project, aimed at investigating agricultural history and irrigation—the salinity of irrigated fields and its impact on social and economic subsystems—mapped the cultural landscape through more than six thousand years. It was the first comprehensive archaeological regional analysis of the Mesopotamian alluvium.

During the 1970s, intensive archaeological rescue operations took place in the Hamrin Basin as a result of construction for a new dam at the point where the Diyala River cuts through the Hamrin Mountains. The aggregated archaeological investigations of the Diyala region have made it one of the best-documented provinces of Mesopotamia.

The excavations at Tell Asmar, Khafajeh, Tell Agrab, and Ishchali resulted in the development of a long-range chronology for the Lower Diyala region. These sites cover a period from the Late Uruk into the Old Babylonian Period (c. 3500–1800 BCE). Their stratigraphic sequences partly overlap and provide the basis for a diachronic study of architecture and artifacts. In 1952, Delougaz (1952) published a comprehensive pottery corpus, still one of the most useful references for studying the third- and early second-millennium BCE pottery of Mesopotamia. The repertoire of seals also has contributed essentially to establishing a sequence for glyptic styles in Mesopotamia (Frankfort, 1955). The architectural remains from the beginning of the third millennium, in particular temple buildings, have resulted in the subdivision of the ED period into three phases: I–III (Delougaz and Lloyd, 1942). The terminology Frankfort and others introduced does differ at some points from that traditionally used (e.g., the Protoliterate period equals the Uruk and Jemdet Nasr periods; late ED III is labeled the Protoimperial period).

Robert McC. Adams's 1957–1958 surveys added details about settlement patterns and canal systems from the Ubaid period through the nineteenth century CE. The intensive investigation of the Hamrin basin by many international archaeological teams extended the chronology for the entire Diyala region and widened its geographic range.

Except for a single aceramic site, the earliest settlements in the Hamrin date to the Samarra period (c. 6000–5500 BCE). This could be expected, as the region is in the middle of traditional Samarran territory, the marginal zones for dry farming. The first substantial human activities can be attributed to the Ubaid period (5500–4000 BCE). At Tell Abada, located south of the Diyala River in the Hamrin, almost an entire Ubaid village was excavated by an Iraqi expedition under the direction of Sabah Abboud Jasim (1985). The village consists of several building compounds in which a central building differs both in size and finds from the rest and suggests an advanced state of social stratification in the order of chiefdoms. Houses show a typical tripartite ground plan, with a T-shaped central room. These are prototypes for the following Uruk and ED temple and house plans. At Tell Madhhur, in the northern part of the Hamrin, a particularly well-preserved house with almost a complete household inventory was excavated by a British-Canadian team (e.g., Roaf, 1989). In the Lower Diyala Region, sparse Ubaid remains were observed, but the location of sites shows the basic outline of the irrigation canal system. There, as at several other Mesopotamian sites, the fact that Ubaid remains were found under the major urban sites shows that the principle urban settlement pattern took shape during the Ubaid with the establishment of villages at natural or artificial watercourses. [See Ubaid.]

Few finds are available from the Uruk period (4000–3100 BCE). In the Hamrin, villages founded during the Ubaid disappear, while in the Lower Diyala region there is an increasing area of land under exploitation. This development can be tied to the urbanization process for the entire region, in which centers experiencing strong population growth became large towns.

During the Jemdet Nasr and Early Dynastic periods (3100–2400 BCE), the Diyala region experienced steady population growth, to judge from the increase in the number of sites and in settlement size. In the Lower Diyala region, urban centers surrounded by a pattern of sites in hierarchical clusters developed at Khafajeh, Tell Asmar, and Tell Agrab. Of ninety-six surveyed sites, ten can be classified as large towns (greater than 10 ha, or 25 acres), nineteen as small towns (4–10 ha, or 9–25 acres), and sixty-seven as villages (fewer than 4 ha, or 9 acres). The ED period is one of the best documented in the region. Extensive excavations at sites in the Lower Diyala and the Hamrin give a comprehensive impression of the architecture, burial traditions, art, and material culture in the early third millennium. At Khafajeh and Tell Asmar, sequences of temples were found, some of them identified by historical sources. In Khafajeh a sequence of temples dedicated to Sin dates back to the Jemdet Nasr period. The temple type is initially tripartite but evolves into a closed compound with internal courtyards. In contrast to contemporary and earlier temples, these temples were originally built on the ground floor. In the ED II period, a large temple complex was constructed at Khafajeh, characterized by two large oval enclosure walls. Between the two walls was a house interpreted as the house of the priest. Inside the oval enclosure walls the temple rose on a platform. It was surrounded by workshops, perhaps a production center administrated by the priest of the temple (Delougaz, 1940). At Tell Agrab a monumental temple was dedicated to Shara. The ground plan shows a traditional Mesopotamian building pattern, in which the cella is located within a large square complex of rooms and courtyards and the entire building is enclosed with a heavy outer wall. At Tell Asmar, the temple sequence produced several spectacular finds. Best known is the hoard of sculptures from the ED II period found in a pit under the floor of the so-called Square Temple. The sculptures are carved in stone and are typically Sumerian in style and dress. ED domestic architecture is less well known. In the Hamrin remains of round structures were found that are dated to the beginning of the ED period. Both at Tell Gubba and Tell Razuk, complete round buildings were preserved to a degree that had left part of the corbelled vaulted ceilings intact. These round structures are assumed to have served as fortifications along the northeastern frontier, constructed and maintained by the large town centers in the Lower Diyala region. One reason for setting up such strongholds was to protect the vulnerable outlets for the vital irrigation canals at the point where the Diyala River cuts through the Hamrin Mountains.

The excavation of ED sites gives detailed insight into the technological and artistic level of the population. In particular many cylinder seals, bronze tools, sculptures, and carved relief plaques were recovered. The pottery tradition during the ED I–II periods shows regionalization at the southeastern fringe of Mesopotamia: polychrome painted Jemdet Nasr pottery develops into local styles; and in the Lower Diyala and the Hamrin, so-called Scarlet Ware, a jar painted in red and black with geometric and naturalistic motifs, appears. This distribution of ceramic styles makes it possible to recognize the Diyala region as one cultural entity during ED I–II.

In the Akkadian period (2400–2200 BCE), the region continues to develop along the lines laid out during the ED period. At Tell Asmar, private houses and monumental buildings have been exposed. The Northern Palace, a large building complex with several domestic sectors, may have already been built at the end of ED III. While the palace was apparently ruined with the Guti invasion at the end of the Akkadian period, the private houses and dwellings continued in use. The town lost its administrative function, but it remained inhabited. In the Hamrin, Akkadian cuneiform tablets have been found, probably within an administrative context (Whiting, 1987).

The archaeological record remains poor through the Ur III dynasty, during which period Eshnunna/Tell Asmar was controlled by governors appointed by the kings of Ur. During the following era, the Isin-Larsa period (c. 2000–1800 BCE), the region reached a political peak, beginning with the move toward independence by the governor of Eshnunna, Ituriya. Although the settlement pattern continued, there was a tendency for a few centers to grow, perhaps as a result of the centralization of administrative institutions and power in Eshnunna. The importance of the region and its history during the Larsa period is well documented because of the finds of archives and inscriptions. Large temple complexes were constructed, and, in the case of the Shu-Sin temple at Eshnunna, the temple was combined with a palace. At Ishchali, the monumental temple of Ishtar-Kititum comprises interior courtyards and broadroom antecella and cella temple plans. From this era, several sites in the Hamrin that most likely profited from the interest of Eshnunna have produced remains, particularly towns that dominated the main routes.

The flourishing of the Diyala during the hegemony of Eshnunna ended with the reign of Hammurabi of Babylon. According to survey results (Adams, 1965), the larger towns entered a period of decline that lasted for several hundreds of years. Data from the Hamrin speak of a population settled primarily in villages scattered over the plains. A regeneration of the settlement pattern and population growth first occurs in the Seleucid-Parthian period. Despite poor archaeological documentation, survey data suggest extensive urbanization. Development culminated in the Sasanian period, during which the region, in ecological terms was brought to its limits. As the agricultural hinterland for the Sasanian capital at Ctesiphon, large canal systems were laid out and the agricultural potential exploided to a maximum. During the Islamic period, the Diyala region again experienced a decline in organization and population size, despite the rise of Baghdad.

[See also Eshnunna; Hamrin Dam Salvage Project; and Khafajeh.]


  • Adams, Robert McC. Land behind Baghdad. Chicago, 1965. The most comprehensive study of ancient settlement patterns in the Diyala.
  • Delougaz, Pinhas. The Temple Oval At Khafajah. University of Chicago, Oriental Institute Publications (OIP), 53. Chicago, 1940. Excavation report.
  • Delougaz, Pinhas, and Seton Lloyd. Pre-Sargonid Temples in the Diyala Region. OIP, 58. Chicago, 1942. Excavation report with a description of the Sumerian temples found at Tell Asmar, Khafajeh, and Tell Agrab (except the Oval Temple).
  • Delougaz, Pinhas. Pottery from the Diyala Region. OIP, 63. Chicago, 1952. The basic reference book for Mesopotamian pottery.
  • Delougaz, Pinhas, et al. Private Houses and Graves in the Diyala Region. OIP, 88. Chicago, 1967.
  • Frankfort, Henri. Sculpture of the Third Millennium B.C. from Tell Asmar and Khafājah. OIP, 44. Chicago, 1939. Detailed presentation of Sumerian sculptures from the Diyala.
  • Frankfort, Henri, Seton Lloyd, and Thorkild Jacobsen. The Gimilsin Temple and the Palace of the Rulers at Tell Asmar. OIP, 43. Chicago, 1940. Excavation report.
  • Frankfort, Henri. More Sculpture from the Diyala Region. OIP, 60. Chicago, 1943. Detailed presentation of Sumerian sculptures from the Diyala. See as well Frankfort (1939).
  • Frankfort, Henri. Stratified Cylinder Seals from the Diyala Region. OIP, 72. Chicago, 1955
  • Gibson, McGuire, ed. Uch Tepe I. The Chicago-Copenhagen Expedition to the Hamrin, Hamrin Report 10. Chicago and Copenhagen, 1981. A broad review of the settlement history and archaeological results from the Hamrin basin, together with a detailed report on the excavation of the ED round fortification at Tell Razuk.
  • Hill, Harold D., et al. Old Babylonian Public Buildings in the Diyala Region. OIP, 98. Chicago, 1990. Conclusive report on the excavations of the Kititum Temple at Ishchali.
  • Jacobsen, Thorkild. Salinity and Irrigation: Agriculture in Antiquity. Bibliotheca Mesopotamica, 14. Malibu, 1982. Based on manuscripts twenty years older than the year of publication.
  • Jasim, Sabah A. The ῾Ubaid Period in Iraq: Recent Excavations in the Hamrin Region. British Archaeological Reports, International Series, no. 267. Oxford, 1985. Report on the important finds of an Ubaid village, with a summary of the Ubaid period in Mesopotamia based on the new finds.
  • Roaf, Michael. “Social Organization and Social Activities at Tell Madhhur.” In Upon This Foundation—the Ubaid Reconsidered, edited by E. F. Henrickson and Ingolf Thuesen, pp. 91–145. Copenhagen, 1989. Comprehensive analysis of an Ubaid period household.
  • Whiting, Robert M., Jr. Old Babylonian Letters from Tell Asmar. University of Chicago, Oriental Institute, Assyriological Studies, 22. Chicago, 1987. The most recent and detailed scholarly work on letters from the archives at Tell Asmar.

Ingolf Thuesen