It is from the period of Hammurabi that southern Iraq came to be known as Babylonia, while the north had already coalesced into Assyria hundreds of years before. However, his empire was short-lived, and rapidly collapsed after his death, with both Assyria and southern Iraq, in the form of the Sealand Dynasty, falling back into native Akkadian hands. The foreign Amorites clung on to power in a once more weak and small Babylonia until it was sacked by the Indo-European speaking Hittite Empire based in Anatolia in 1595 BC. After this, another foreign people, the Language Isolate speaking Kassites, originating in the Zagros Mountains of Ancient Iran, seized control of Babylonia, where they were to rule for almost 600 years, by far the longest dynasty ever to rule in Babylon.