Enmebaragesi (Sumerian:𒂗𒈨𒁈𒄄𒋛) originally Mebarasi (Sumerian:𒈨𒁈𒋛) was the penultimate king of the first dynasty of Kish reigning circa the 26th century BCa according to the Sumerian King List. The same source adds that he subdued Elam, and reigned 900 years. Like his son and successor Aga he reigned during the Kish hegemony over Sumer. Enmebaragesi signals a momentous documentary leap from legend to history, from fiction to history, since he is the earliest ruler on the king list whose name is attested directly from archaeology.
Four inscriptions have been found with the name Mebaragesi, one particular inscription of unknown provenance in the Baghdad Museum reads 𒈨𒁈𒋛 𒈗 [[Kish (Sumer)
|𒆧]] ("Mebaragsi, King of Kish"), which can be dated on palaeographic grounds to the Early Dynastic Period based on the very archaic form of the sign Kish, still showing the horns of the aurochs’ heads at the origin of the grapheme.
Another vessel fragment from Khafaja, inscribed with the name Me-barag-[si] is usually also attributed to the king of Kish. However, the dating of the piece is from the ED IIIa, and the Bara2 (𒁈) of the inscription is different shaped, probably mentioning another Mebaragesi which wasn't a king. This theory has been criticized by Piotr Steinkeller by "the fact that a votive inscription was discovered in a particular level does not necessarily mean that it dates to that level." 
He is also attested in the Sumerian King List (ETCSL2.1.1) and in the Tummal InscriptionETCSL (2.1.3), both as the father of Aga of Kish and the first builder of the temple:
Enmebaragesi, the king in this very city (Nippur), built the House of Enlil, Agga the son of Enmebaragesi, made the Tummal pre-eminent.
Enmebaragesi is also mentioned Gilgamesh and Aga as the father of Aga who laid siege to Uruk, and in The lord to the Living One's Mountain which is offered as Gilgamesh's sister to be the wife of Huwawa.
According to the Sumerian King List (ETCSL2.1.1), Kish had the hegemony over the entire territory of northern Babylonia and the most northern section of southern Babylonia cities such as Nippur, Isin, and Eresh, and large portions of the Diyala Region. Succeeding Iltasadum on the throne, where he reigned 900 years, leading a successful campaign against Elam and capturing Dumuzid the Fisherman in Uruk. There is some scant evidence to suggest that like the later Ur III kings, the rulers of ED Kish sought to ingratiate themselves to the authorities in Nippur, possibly to legitimize a claim for leadership over the land of Sumer or at least part of it. The use of the royal title King of Kish expressing a claim of national rulership owes its prestige to the fact that Kish once did rule the entire nation. Archeology evidence from Kish shows a city flourishing in ED II with its political influence extending beyond the territory, however in ED III the city declined rapidly.
The Sumerian King List recounts "En-me(n)-barage-si, the one who carried away as spoil the weapons of the land of Elam, became king."
A tradition of the Kishite expansion into the Susiana and Iranian plateau are reflected in an inscription of an ED II king of Kish named Enna-il, which commemorates his military operations in Elam. The Discoveries of the inscriptions of Enmebaragesi and an unidentified king of Kish at Khafajah and Tell Agrab respectively are convincing indicators of the Kišite presence in the Diyala Region.
While the Sumerian King List (only in one version) mentions that Dumuzid the Fisherman king of Uruk captured Enmebaragesi, a new translation has been made, which exchanges Enmebaragesi as the one who captured Dumuzid.
Sumerian King List translations
Šu aš en?-me-barag-ge4?-e-si nam-ra [i3?]-ak?
Single handed he (Dumuzid) captured En-me-barage-si.
[Šu aš] en?-me-[barag-ge4?-e-si-ta] nam-ra [ak]
He (Dumuzid) was taken captive by the (single) hand of Enmebaragesi.
This allows a better perspective on the political and military struggle between Kish and Uruk, the short duration of Dumuzid rulership and why he had no hereditary successors. After the general-king Lugalbanda in Uruk, a man named from Kuara seized the throne. Enmebaragesi attacked Uruk, captured Dumuzid and subjugated the city placing Gilgamesh as his vassal-king.
The later Sumerian Renaissance (Ur III) king Shulgi addressed one of his praise poems (Shulgi Hymn O (ETCSL2.1.1)) to Gilgamesh, that credits him with capturing and defeating Enmebaragesi of Kish instead of his son Aga as Gilgamesh and Aga recounts. While in the historical scene of the Early Dynastic period this is quite conceivable,d the assumption of two different wars is difficult to uphold because Gilgamesh emerges as victorious in both; his first victory would imply defeat and submission by the kingdom of Kish.
Since Gilgamesh addresses Aga denoting military relations between them in the past and indebtedness to him for saving his life leads to Gilgamesh being dependent on Aga previously, conflicting with the assumption that he won a previous war against Kish.
Another theory is since Enmebaragesi established the hegemony of Kish, defeating Aga would be less impressive than his powerful father, who therefore served the purpose of the hymn and portrays Gilgamesh as a mighty figure. Since Enmebaragesi was inserted to replace Aga, the hymn doesn't reflect a separate but rather one literary tradition from the tale.
c.^ The word men is rather uncommon in the Fara personal names, appearing only seven times. One of those names Men-pa-e2 only appears five times, while it's graphic variación ME-pa-e2 is attested 37 times.
d.^ The prolonged war between Lagash and Umma, known from the inscriptions of five consecutive kings of Lagash.
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