Between the late fourth millennium and the second millennium BC, two civilizations appeared on the eastern coasts of the peninsula. The first was Dilmun, which made the island of Bahrain its capital and extended from present-day Kuwait and the eastern coasts of Saudi Arabia all the way to Qatar.
- The second is the Magan civilization, which today includes both Oman and the Emirates. Dilmun, especially its capital, Bahrain Island, emerged as a major trading point, due to its strategic location linking Sumer and the Indus Valley, in addition to the ease of anchorage for ships and the abundance of its groundwater. It has reached an extreme stage of prosperity.
- This prosperity made Dilmun an icon for the Sumerians, as it was paradise in their eyes, as they believed it was the home of the ancient gods, the place of the first creation, and later the landing pad for Ziusudra’s ship in the Samaritan story of the flood. Some believe that the reason for their attachment to it is because it is their origin, from which they migrated to Mesopotamia.
- As for the Magan civilization, its forests and mines were a primary source of wood and copper exported to Sumer (the Sumerians mentioned it in their correspondence and legends as well). Of course, the wealth and prosperity enjoyed by both civilizations made them the target of foreign ambitions, and they were later exposed to the Akkadian invasion.
- Because everything has an end, their confinement began at the beginning of the second millennium BC. As a result of several variables, such as the collapse of the Indus Valley Civilization and the First Babylonian Kingdom, in addition to the availability of other sources of copper, such as Anatolia and Cyprus, which led to the loss of their commercial status. To follow after it under the influence of the kingdoms of southern Mesopotamia, such as the Kassites. What is interesting is that the Kassites mentioned, during their rule of Dilmun, the raids of the Akhlamu (a semi-nomadic Semitic people who inhabited the areas west of the Euphrates) on the areas of Dilmun and the plundering of its fruit crops (dates) and their constant threats.