Assyria was originally an Akkadian kingdom which evolved in the 25th to 24th Centuries BCE.
Originally, the earliest Assyrian kings such as Tudiyaare minor rulers, and after the founding of the Akkadian Empire which lasted from 2334 BCE to 2154 BCE subject to Sargon of Akkad who united all the Akkadian and Sumerian speaking peoples of Mesopotamia under one rule.The Akkadian nation of Assyria (and from 1894 BCE, Babylonia) largely evolved from the dissolution of the Akkadian Empire.
In the Old Assyrian period of the Early Bronze Age, Assyria had been a kingdom of northern Mesopotamia (modern-day northern Iraq), competing for dominance initially with the ancient Sumero-Akkadian "city states" such as Isin, Ur and Larsa, and later with Babylonia which was founded by Amorites in 1894 BCE, and often under Kassite rule.
During the 20th century BCE, it established colonies in Asia Minor, and under the 20th Century BC King Ilushuma, Assyria conducted many successful raids against the states of the south.
It had experienced fluctuating fortunes in the Middle Assyrian period.
Assyria had a period of empire under Shamshi-Adad I in the late 19th to mid 18th centuries BCE, following this it found itself under short periods of Babylonian and Mitanni-Hurrian domination in the 17th and 15th Centuries BC respectively, followed by another period of great power and empire from 1365 BCE to 1074 BCE, that included the reigns of great kings such as Ashur-uballit I, Tukulti-Ninurta I and Tiglath-Pileser I.
During the ancient 'Dark Ages' Assyria remained a strong and stable nation, unlike its rivals.
Scholars variously date the beginning of the "Middle Assyrian period" to either the fall of the Old Assyrian kingdom of Shamshi-Adad I, or to the ascension of Ashur-uballit I to the throne of Assyria.
