Assyria was originally a region on the Upper Tigris river, named for its original capital, the ancient city of Assur. Later, as a nation and empire that came to control all of the Fertile Crescent, Egypt and much of Anatolia, the term "Assyria proper" referred to roughly the northern half of Mesopotamia (the southern half being Babylonia), with Nineveh as its capital.
The Assyrians were warriors, who invented excavation to underminecity walls, battering rams to knock down gates, as well as the concept of a corps of engineers, who bridged rivers with pontoons or provided soldiers with inflatable skins for swimming. The Assyrian kings controlled a large kingdom at three different times in history. These are called the Old (20th – 15th centuries BC), Middle (15th – 10th centuries BC), and Neo-Assyrian (911 – 612 BC) kingdoms, of which the last is the most well known and best documented.
...The Akkadian Empire was centered in Akkad, an ancient city in central Mesopotamia. Despite its ancient importance, the city of Akkad has not yet been located. It was probably situated on the west bank of the Euphrates, between Sippar and Kish (ca 50 km (31 mi) southwest of Baghdad).
The Akkadian Empire reached the height of its power between the 23rd and 22nd centuries BC, following the conquests of king Sargon of Akkad.
Because of the policies of the Akkadian Empire toward linguistic assimilation, the predominant Semitic dialect was named the Akkadian language, reflected in the word akkadû ("in the language of Akkad") during the Old Babylonian period to denote a Semitic-language version of a Sumerian text.