Uruk period followed by Jemdet Nasr period
Jemdet Nasr period
This phase of "Late Uruk" is followed by another phase (level III of Eanna) in which the Uruk civilization declined and a number of distinct local cultures developed throughout the Near East.  This is generally known as the Jemdet Nasr period, after the archaeological site of that name. Its exact nature is highly debated, and it is difficult to clearly distinguish its traits from those of the Uruk culture, so some scholars refer to it as the "Final Uruk" period instead. It lasted from around 3000 to 2900 BC.Alternative chronology
In 2001, a new chronology was proposed by the members of a colloquium at Santa Fe, based on recent excavations, especially at sites outside Mesopotamia. They consider the Uruk period to be the "Late Chalcolithic" (LC). Their LC 1 corresponds to the end of the Ubaid period and ends around 4200 BC, with the beginning of LC 2, which is the first phase of the Uruk period. They divide "Old Uruk" into two phases, with the dividing line placed around 4000 BC. Around 3800 BC, LC 3 begins, which corresponds to the "Middle Uruk" phase and continues until around 3400 BC, when it is succeeded by LC 4. It rapidly transitions to LC 5 (Late Uruk), which continues until 3000 BC.Some other chronological proposals have also been put forward, such as by the ARCANE team (Associated Regional Chronologies for the Ancient Near East).Although the chronology of the Uruk period is full of uncertainties, it is generally agreed to have a rough span of a thousand years covering the period from 4000 to 3000 BC and to be divided into several phases: an initial urbanisation and elaboration of Urukian cultural traits marks the transition from the end of the Ubaid period (Old Uruk), then a period of expansion (Middle Uruk), with a peak during which the characteristic traits of the 'Uruk civilization' are definitively established (Late Uruk), and then a retreat of Urukian influence and increase in cultural diversity in the Near East along with a decline of the 'centre'.
Some researchers have attempted to explain this final stage as the arrival of new populations of Semitic origin (the future Akkadians), but there is no conclusive proof of this. In Lower Mesopotamia, the researchers identify this as the Jemdet Nasr period, which sees a shift to more concentrated habitation, undoubtedly accompanied by a reorganisation of power; in southwestern Iran, it is the Proto-Elamite period; Niniveh V in Upper Mesopotamia (which follows the Gawra culture); the "Scarlet Ware" culture in Diyala. In Lower Mesopotamia, the Early Dynastic Period begins around the start of the 3rd millennium BC, during which this region again exerts considerable influence over its neighbours.The function of these buildings, which are unparalleled in their size and the fact that they are gathered in monumental groups, is debated. The excavators of the site wanted to see them as 'temples', influenced by the fact that in the historic period, the Eanna was the area dedicated to the goddess Inanna and the other sector was dedicated to the god An. This conformed to the theory of the 'temple-city' which was in vogue during the inter-war period. It is possible that this is actually a place of power formed by a complex of buildings of different forms (palatial residences, administrative spaces, palace chapels), desired by the dominant power in the city, whose nature is still unclear. In any case, it was necessary to invest considerable effort to construct these buildings, which shows the capacities of the elites of this period. Uruk is also the site of the most important discoveries of early writing tablets, in levels IV and III, in a context where they had been disposed of, which means that the context in which they were created is not known to us. Uruk III, which corresponds to the Jemdet Nasr period, sees a complete reorganisation of the Eanna quarter, in which the buildings on the site were razed and replaced by a grand terrace, which ignores the earlier buildings. In their foundations, a deposit which is probably of a cultic nature (the Sammelfund) was found, containing some major artistic works of the period (large cultic vase, cylinder seals, etc.).