The First Dynasty, an unbroken succession of Amorite kings, lasted 300 years despite a major rebellion. Babylon had close relationships with the nearby cities Sippar, Kish, and Borsippa. Trade and alliances reached much further. The Sumerian king-lists of earlier times were replaced by Babylonian equivalents, various cities having their own version. Kings briefly recorded major events; names were given to each year of their reign for dating documents. Trade was widespread, by canal and river, or overland by donkey. Royal edicts excluded certain groups from trade. Evidence comes from a profusion of clay tablets. Official letters are plentiful. Priestesses of Marduk carried out trade for Babylon in other cities. The temple of Marduk was built and furnished with a golden throne. Elamite control over several major cities, which left its mark on temple design, was ended by Hammurabi late in his reign; there is a possible connection with Genesis 14:1–16. Regular edicts were issued to release individuals from debt and to regulate trade. The main powers were Halab (Aleppo), Eshnunna, and Larsa, until Hammurabi achieved supremacy and claimed divinity. His successor Samsu-iluna followed his father’s example.

Although Assyrian merchants lived in Central Anatolia for over two centuries and used writing extensively for their business local Anatolians only became interested in the use of script toward the end of the Old Assyrian Period. This coincided with the emergence of the first unified Anatolian kingdom under Anitta. It is argued that the so-called Anitta Text, known only from later copies in Hittite, could only have been written in Assyrian in Old Assyrian cuneiform.