From what is known, the Kassites took control of the city of Babylon and the region of Babylonia sometime in the early sixteenth century BC, with their first king, Agum II, bringing the sacred statue of the city’s god Marduk back from its Hittite captivity around the year 1570 BC. <ref> Brinkman, J.A. “Foreign Relations of Babylonia from 1600 to 625 B.C.: The Documentary Evidence.” <i>American Journal of Archaeology</i> 76 (1972) p. 272</ref> Once the Kassites had established themselves as rulers of Babylon, though, apart from keeping their distinct names and their language in daily use, they became true Babylonians, worshipping Marduk and the other deities of the city and keeping the proper cultic rituals. <ref>Kuhrt, p. 333</ref>
To keep cultural continuity in Babylon and no doubt to appear as legitimate rulers to non-Kassites, the Kassites continued the tradition of using the Sumerian and Akkadian languages in their inscriptions and religious rituals. <ref>Kuhrt, p. 338</ref> The Kassites, though, also offered an important linguistic innovation to Mesopotamia. The Kassites brought the dialect of Akkadian into Babylon which morphed into the “standard Babylonian” used by later groups such as the Assyrians and Neo-Babylonians. <ref> Mieroop, Marc van de. <i>A History of the Ancient Near East: ca. 3000-323 BC.</i> 2nd ed. (London: Blackwell, 2007), p. 177</ref>
As the Kassites pursued a policy of cultural continuity in Babylon, they embarked on an aggressive campaign of conquest throughout the rest of Mesopotamia.
===The Expansion of Kassite Power===