The rulers of this dynasty are believed to have r. c. 2570 – c. 2350, c. 2494 – c. 2342 BCE. Although the first dynasty of Lagash has become well-attested through several important monuments, many archaeological finds, and well-known based off of mentions on inscriptions contemporaneous with other dynasties from the EDIII period; it was not inscribed onto the SKL. One fragmentary supplement names the rulers of Lagash. The first dynasty of Lagash preceded the dynasty of Akkad in a time in which Lagash exercised considerable influence in the region.
Enhengal (r. c. 2570 – c. 2510, c. 2530 – c. 2510 BCE) is recorded as the first known ruler of Lagash, being tributary to Uruk. His successor Lugalshaengur (r. c. 2510 – c. 2494 BCE) was similarly tributary to Mesilim. Following the hegemony of Mesannepada, Ur-Nanshe (r. c. 2494 – c. 2465 BC) succeeded Lugalshaengur as the new high priest of Lagash and achieved independence, making himself king. He defeated Ur and captured the king of Umma, Pabilgaltuk. In the ruins of a building attached by him to the temple of Ningirsu, terracotta bas reliefs of the king and his sons have been found, as well as onyx plates and lions' heads in onyx reminiscent of Egyptian work. One inscription states that ships of Dilmun (Bahrain) brought him wood as tribute from foreign lands. He was succeeded by his son Akurgal (r. c. 2466 – c. 2457, c. 2464 – c. 2455 BCE).
Although short-lived, one of the first empires known to history was that of Eannatum (r. c. 2457 – c. 2425, c. 2455 – c. 2425 BCE), grandson of Ur-Nanshe, who made himself master of the whole of the country of Sumer by annexing the cities of Uruk, Ur, Nippur, Akshak, and Larsa. Umma was made tributary (after he vanquished Ush)—a certain amount of grain being levied upon each person in it, that had to be paid into the treasury of the goddess Nina and the god Ningirsu; in addition, Eannatum's campaigns extended beyond the confines of Sumer as he overran a part of Elam, took the city of Az on the Persian gulf, and exacted tribute as far as Mari. Many of the realms he conquered were often in revolt; furthermore, he seems to have used terror as a matter of policy. His Stele of the Vultures depicts vultures pecking at the severed heads and other body parts of his enemies. During his reign, temples and palaces were repaired or erected at Lagash and elsewhere; the town of Nina—that probably gave its name to the later Niniveh—was rebuilt, and canals and reservoirs were excavated. He also annexed the kingdom of Kish; however, it recovered its independence after his death. His empire collapsed shortly after his death.
Eannatum was succeeded by his brother, Enannatum I (r. c. 2424 – c. 2421, c. 2425 – c. 2405 BCE). During his rule, Umma once more asserted independence under Ur-Lumma, who attacked Lagash unsuccessfully. Ur-Lumma was replaced by a priest-king, Illi, who also attacked Lagash.
His son and successor Entemena (r. c. 2420 – c. 2393, c. 2405 – c. 2375 BCE) restored the prestige of Lagash. Illi of Umma was subdued, with the help of his ally Lugal-kinishe-dudu of Uruk, successor to Enshakushana and also on the king-list. Lugal-kinishe-dudu seems to have been the prominent figure at the time, since he also claimed to rule Kish and Ur. A silver vase dedicated by Entemena to his god is now in the Louvre. A frieze of lions devouring ibexes and deer, incised with great artistic skill, runs round the neck, while the eagle crest of Lagash adorns the globular part. The vase is a proof of the high degree of excellence to which the goldsmith's art had already attained. A vase of calcite, also dedicated by Entemena, has been found at Nippur. After Entemena, a series of weak, corrupt rulers is attested for Lagash: Enannatum II, Enentarzi, Enlitarzi, and Lugalanda who altogether r. c. 2392 – c. 2361, c. 2375 – c. 2352 BCE. The last of these, Urukagina (r. c. 2361 – c. 2350, c. 2352 – c. 2342 BCE), was known for his judicial, social, and economic reforms (as part of the Code of Urukagina), and his may well be the first legal code known to have existed.
Later, Lugal-Zage-Si, the priest-king of Umma, overthrew the primacy of the Lagash dynasty in the area, then conquered Uruk, making it his capital, and claimed an empire extending from the Persian Gulf to the Mediterranean. He was the last ethnically Sumerian king before Sargon of Akkad.