Gutian period
The Gutian kings came to some power in Mesopotamia in ca. the 22nd century BC (short chronology) by destabilising Akkad at the end of the reign of Shar-kali-sharri. They were invaders from a people known as Guti or Gutii, who inhabited the Zagros Mountains. The last Gutian king was Tirigan, who was preceded by 21 kings (each reigning for only a few years), reigning roughly a total of one century (estimates vary between 80 and 120 years, with 91 years often quoted as probable). The dynasty was succeeded by the 3rd dynasty of Ur.
The Gutian kings were, in order:
Inkishuc, Zarl-agab, Shulme, Silulumesh, Inimabakesh, Igecaush, Yarl-agab, Ibate, Yarl-angab, Kurum, Apil-kin, La-erabum, Irarum, Ibranum, Hablum, Puzur-Suen, Yarlaganda and Tirigan.
History
In the time of the Akkadian Empire, one prominent nomad tribe were the Guti, who lived in the Zagros Mountains. A generation after Naram-Sin's death, the Guti saw their chance. The weak successors of the king were fighting among themselves for the throne, and various provinces were in revolt and eager for nomad help. The Guti swept down, defeated the demoralized Akkadian army, took Agade and destroyed it about 2215 BC. The Empire became theirs.
Agade was so thoroughly destroyed that, alone of all the Mesopotamian capitals, its site is still not known. The Guti proved to be poor rulers. Under their crude rule, prosperity declined. They were too unused to the complexities of civilization to organize matters properly, particularly in connection with the canal network. This was allowed to sink into disrepair, with famine and death resulting. Thus a short "dark age" swept over Mesopotamia.
Akkad bore the brunt of this, for it was Akkad that had been the center of the Empire and bore the prestige of its tradition, so that it was in Akkad that the Guti established their own center in place of the destroyed Agade. Some of the Sumerian cities in the south took advantage of the safety of distance and purchased a certain amount of self-government by paying tribute to the new rulers.
Uruk got along under its 4th Dynasty and Ur under its 2nd Dynasty. The most remarkable ruler of the Gutian period was however not a Guti, but the governer of Lagash, Gudea. Under him about 2150 BC, Lagash had a golden age.
After a few kings the Gutian kings quickly became cultivated kings. They probably even strove to become more Akkadian than the Akkadians, since they had a nomadic ancestry to live down. Thus the nomad rule ends by absorption. Frequently though, such absorption isn't enough, the Guti lasted only about a century. At about 2120 BC, they were expelled from Mesopotamia by the rulers of Uruk and Ur. From this point on the Guti's disappear from history.
See also Sumerian king list.