The warring Hurrian tribes and city states are believed to have become united under one dynasty after the collapse of Babylon following its sack by the Hittite king Mursili I and the Kassite invasion.

The Hittite conquest of Aleppo (Yamhad), the weak middle Assyrian kings, and the internal strife of the Hittites had created a power vacuum in upper Mesopotamia, leading to the formation of the kingdom of Mitanni.

…then, to deprive the Hittites of access to northern Syria, establish a southeastern kingdom, Hanilgalbat.

The Hittite conquest of Yamhad, an Amorite kingdom centered at Hala (Aleppo) in northern Syria, the weak middle Assyrian kings, and the internal strivings of the Hittites had created a power vacuum in upper Mesopotamia, where a substantial Hurrian population had also settled, their culture influencing the area.

It is believed that the warring Hurrian tribes and city states had become united under one dynasty after the collapse of Babylon due to the Hittite sack by Mursili I and the Kassite invasion.

This leads to the formation of the kingdom of Mitanni, or Hanigalbat, around 1500 by a legendary king called Kirta.

The territory of Mitanni, or Hanigalbat, extends from the region of Kirkuk in the east westward through Syria to the Mediterranean Sea by the early fifteenth century BCE.

The erection of the Mittani kingdom prompts Egypt to wage war.

A successful military campaign regains control of Palestine and enters northern Syria.

Egyptian forces reach as far as the east bank of the Euphrates to temporarily defeat Mitanni, but fail to wrest domination of Syria from the rival power.

The Hurrians, who have established several commercial centers in northwestern Mesopotamia, have expanded westward and southward to dominate eastern Anatolia and northern Syria.

Yet, the Hurrian heartland during this period is northern Mesopotamia, the country known at this time as Hurri, where the political units are dominated by dynasts of Indo-Iranian origin.

The Hittite conquest of Aleppo (Yamhad), the weakened Assyrian kings, and the internal strife among the Hittites had created a power vacuum in upper Mesopotamia.

This had led to the formation of the kingdom of Mitanni, thought to have been a feudal state led by a ruling Indo-Iranian noble class.

This group, called maryannu, had moved rapidly into Northern Mesopotamia with the aid of the chariot and united the warring Hurrian tribes and city states under one dynasty in a loosely organized Hurrian-speaking state with its capital at Washshukanni, near modern Urfa.

The Hurrians, having established several commercial centers in northwestern Mesopotamia, have by about 1500 BCE expanded westward and southward to dominate eastern Anatolia and northern Syria.

They are the rulers of the kingdom of Mitanni, which wars with Egypt over Syria in 1470.

Telepinu had been able to recover a little ground from the Hurrians of Mitanni, by forming an alliance with the Hurrians of Kizzuwatna; however, with the end of his reign after about 1460, the Hittite Empire has entered a temporary "Dark Ages", the Middle Kingdom, lasting around thirty to seventy years, when records become too scanty to draw many conclusions.

The Middle Kingdom of the Hittites is not so much an independent phase of Hittite history as a period of transition between the Old and New Kingdoms.

Almost nothing is known about the Hittites in this period.

King Barattarna of Mitanni has expanded the kingdom west to Halab (Aleppo) and made a vassal of Idrimi, the vigorous ruler of the city-state of Alalakh.

The Luwian-Hurrian state of Kizzuwatna in the west, whose king, Pilliya, had signed a treaty with Idrimi, has also shifted its allegiance to Mitanni.

Barattarna may have been the Mitannian king the Egyptian Pharaoh Thutmose III encountered by the river Euphrates in his campaign of year 1447 BCE.

This can however only be deduced by comparing the chronology of ancient Egypt and Mitanni at a later date and working back the figures.

Shaushtatar is the son of Parshatatar.

By the time he ascends the throne at some time in the fifteenth century BCE, his father has installed Hurrian client kings in a number of cities, making it easier for Shaushtatar to make Mittani a Mesopotamian power.

Now freed from the constant threat undergone by Mitanni of the Egyptians, Shaushtatar turns his attention toward Assyria.

In a treaty made more than a century later, Shaushtatar is told to have sacked Assur, the Assyrian capital.

He is reputed to have brought the golden doors of the palace to his own capital of Washshukanni, making vassal states of Assyria and Arrapha.

After his invasion of Assyria, Shaushtatar turns his army westward across the Euphrates, along the way gathering beneath his sway all the northern Syrian states as he brings his army to the Mediterranean coast.

He is looking to extend Mitanni's power further south, perhaps into Palestine.

However, much of southern Syria still lies within the Egyptian sphere of influence, which has long been a threat to Mitanni.