A universally accepted chronology for the entire ancient Near East remains to be established. On the basis of the Royal Canon of Ptolemy, a second-century A.D. astronomer, regnal dates can be determined with certainty in Babylonia only as far back as 747 B.C. (the accession of King Nabonassar). Through the use of excavated royal annals and chronicles, together with lists of annually appointed limmu-officials, the chronology of Assyria can be confidently extended back to 911 B.C. (the accession of King Adad-nirari II). The earliest certain link with Egypt is 664 B.C., the date of the Assyrian sack of the Egyptian capital at Thebes. Although it is often possible to locate earlier events quite precisely relative to each other, neither surviving contemporary documents nor scientific dating methods such as carbon 14, dendrochronology, thermoluminescence, and archaeoastronomy are able to provide the required accuracy to fix these events absolutely in time. The West Asian portion of the Timeline therefore employs the common practice of using, without prejudice, the so-called Middle Chronology, where events are dated relative to the reign of King Hammurabi of Babylon, which is defined as being ca. 1792–1750 B.C.
Beginning in the eighth millennium B.C., agricultural communities form in western Iran. It is not clear if these represent an indigenous development or are the result of outside influences. By the end of the fifth millennium B.C., several settlements had grown considerably. The site of Susa is founded at this time with its political and artistic affiliation alternating between the nearby lowland cities of southern Mesopotamia and the highland civilizations of Iran. During the third millennium B.C., an Elamite kingdom emerges centered on the cities of Susa and Anshan, the latter in the Zagros Mountains.
