The Akkadian Empire (/əˈkeɪdiən/) was the first known ancient empire of Mesopotamia, succeeding the long-lived civilization of Sumer. Centered on the city of Akkad (/ˈækæd/) and its surrounding region, the empire united Akkadian and Sumerian speakers under one rule and exercised significant influence across Mesopotamia, the Levant, and Anatolia, sending military expeditions as far south as Dilmun and Magan (modern United Arab Emirates, Saudi Arabia, Bahrain, Qatar and Oman) in the Arabian Peninsula.