Estimation: Akkad, capital of the Akkadian Empire becomes the largest city of the world, taking the lead from Memphis, capital of Egypt.[1] Akkad (or Agade) was a city and its region of northern Mesopotamia, situated on the left bank of the Euphrates, between Sippar and Kish (located in present-day Iraq, ca. ... The Akkadian Empire usually refers to the Semitic speaking state that grew up around the city of Akkad north of Sumer, and reached its greatest extent under Sargon of Akkad. ... Memphis was the ancient capital of the first nome of Lower Egypt, and of the Old Kingdom of Egypt from its foundation until around 1300 BC. Its Ancient Egyptian name was Ineb Hedj (The White Walls). The name Memphis is the Greek deformation of the Egyptian name of Pepi I...