Earlier this king's name was read Entemena due to the ligature [ME:TE] that appears in the ED IIIb writing of his name. As pointed out by B. Alster however (JCS 26, 1974, 178-180), Sargonic period writings spell the name as it is currently read.
Enmetena's legacy survives for us via 27 inscriptions, which attest to a number of renovation projects, new buildings, and events occurring during his reign. He did work on the ancient Antasura and the Eninnu of Ningirsu, in addition to completing the renovation of the Dugru temple begun under his father Enanatum. He built temples to Gatumdug the mother of Lagash and to Ninhursag, as well as a weir on the Lummagimdug canal with a huge storage capacity. He also made the unprecedented decision to introduce an Enlil cult into the Lagash state with the building of a temple he called the E-adda (house of the father). However the attempted introduction was not long-lived, as there is no record of a temple for Enlil in the state in neo-Sumerian times (Bauer pg. 470).
Since the time of Eanatum Lagash had enjoyed a certain hegemony over other city-states in its vicinity. Such was the still the case in the time of Enmetena, as his inscriptions indicate that he held some degree of control over Badtabira, Uruk, and Larsa, imposing corvee labor for state building projects (Bauer pg. 471). One widely copied inscription of Enmetena's (FAOS 05/1 Ent. 45 A) indicates that the king entered into a 'brothership' (NAM.SHESH) pact with Lugalkineshdudu of Uruk upon completion of the Emush temple.
Like his father Enantatum, Enmetena faced an attack by Ur-Lumma into Lagash's part of the Guedena. There are two cone inscriptions of his which summarize the history of the border war and describe the king's own involvement in the affair (FAOS 05/1 Ent. 28 A and FAOS 05/1 Ent. 28 B). In them Enmetena states that he defeated Ur-Lumma in battle and sent him fleeing back to Umma, forcing him to abandon his contingent of 60 chariot teams at the Lummagirnunta canal for the Lagash forces to slaughter, and heaping the corpses into five burial mounds on the plains (Ent. 28 A III 19-27). Ur-Lumma himself was killed in his own state.
However Enmetena continued to have problems with Ur-Lumma's successor, Il, who was previously the chief temple-administrator of Zabalam. Although Il paid back a portion of the grain that Umma owed to Lagash, he invaded the Guedena again. Enmetena apparently stopped him, as he states simply that Enlil and Ninhursag did not allow Il to succeed in his claims, and concludes the inscription with execrations against future attacks from Umma. However the lack of reference to a specific confrontation and the statement that Enmetena dug a new canal off the Tigris river (Ent. 28 A V 9-11) may indicate the situation was handled through non-violent means (see also Bauer 473).