After the emergence of which empire, the Akkad came to designate the area between Nippur and Sippar?
Akkadian Empire The Akkadian Empire was the first ancient Semitic-speaking empire of Mesopotamia, centered in the city of Akkad and its surrounding region, also called Akkad in ancient Mesopotamia in the Bible. The empire united Akkadian and Sumerian speakers under one rule. The Akkadian Empire exercised influence across Mesopotamia, the Levant, and Anatolia, sending military expeditions as far south as Dilmun and Magan (modern Bahrain and Oman) in the Arabian Peninsula.
Hephthalite Empire The Hephthalites (or Ephthalites) were a people of Central Asia who were militarily important circa 450-560. They were based in Bactria and expanded east to the Tarim Basin, west to Sogdia and south through Afghanistan to northern India. They were a tribal confederation and included both nomadic and urban, settled communities. They were part of the four major "Hunic" states known collectively as Xionites or "Hunas", being preceeded by the Kidarites, and succeeded by the Alchon Huns and lastly the Nezak Huns. The Sveta Huna or "White Huns" who invaded northern India are probably the Ephthalites, but the exact relation is not clear.