The city dates from the Ubaid period circa 3800 BCE, and is recorded in written history as a city-state from the 26th century BCE, its first recorded king being Mesannepada. The city's patron deity was Nanna (in Akkadian, Sin), the Sumerian and Akkadian (Assyrian-Babylonian) moon god, and the name of the city is in origin derived from the god's name. UNUGKI, literally "the abode (UNUG) of Nanna".

The site is marked by the partially restored ruins of the Ziggurat of Ur, which contained the shrine of Nanna, excavated in the 1930s. The temple was built in the 21st century BCE (short chronology), during the reign of Ur-Nammu and was reconstructed in the 6th century BCE by Nabonidus, the last king of ancient Babylon. The ruins cover an area of 1,200 metres (3,900 feet) northwest to southeast by 800 metres (2,600 feet) northeast to southwest and rise up to about 20 metres (66 feet) above the present plain level.

circa 2100 BCE

Ubaid Period
Ur’s earliest known occupation traces back to the Ubaid period (circa 5000–4100 BCE), when it began as a small, low-lying settlement on the edge of the Euphrates River. The Ubaid culture is marked by mudbrick architecture, painted pottery, and irrigation-based agriculture. While specific records from this time are scarce, archaeological layers at Ur (Tell al-Muqayyar) show continuity with broader Ubaid cultural patterns, including the emergence of temple institutions and social stratification, possibly laying the foundation for its later sacred status.

Uruk Period
During the Uruk period (circa 4100–2900 BCE), Ur developed into a more complex urban center influenced by the growing network of southern Mesopotamian cities. Monumental architecture, including early temples, appears in this era, likely precursors to later ziggurats. Though overshadowed by the city of ancient Uruk during this time, Ur was already showing signs of centralized administration and craft specialization. It participated in long-distance trade and may have had a role in the expanding system of writing, bureaucracy, and religious hierarchy.

Early Dynastic Period
By the Early Dynastic period (circa 2900–2350 BCE), Ur had emerged as a significant city-state with its own dynastic rulers. The Royal Cemetery of Ur, excavated by Sir Leonard Woolley, dates to this era and contains over 2,000 burials, including those of elite individuals such as Queen Puabi, buried with lavish grave goods and sacrificial retainers. These findings reveal a highly stratified society with strong religious and political institutions. Ur also appears in early Sumerian king lists, sometimes exercising regional influence and engaging in conflicts with neighboring polities like Lagash and Umma.

Akkadian Period
Under Sargon of Akkad and his successors (circa 2350–2150 BCE), Ur was incorporated into the first true Mesopotamian empire. The city retained religious importance and administrative functions under Akkadian rule. Akkadian royal inscriptions mention governors (ensi) appointed in Ur, and the city played a strategic economic role within the imperial network. Artifacts from this period show Akkadian cultural influence, particularly in language and iconography.

Ur III Period / Neo-Sumerian Period
This period (circa 2112–2004 BCE) marks Ur's golden age under the Third Dynasty of Ur, founded by Ur-Nammu and continued by Shulgi and their successors. Ur became the capital of a centralized empire that controlled much of Sumer and Akkad. The city was transformed with monumental architecture, including the great Ziggurat of Ur, and a sophisticated bureaucracy that produced thousands of cuneiform administrative tablets. Law codes, standardized weights, and a state-sponsored economy characterize this era. The dynasty collapsed around 2004 BCE, likely due to Elamite invasions and internal decline.

Old Babylonian Period
After the fall of Ur III and start of the Old Babylonian period (circa 2000–1600 BCE), Ur came under the control of the Isin and then Larsa dynasties, before being absorbed by Hammurabi's Babylon. Though no longer a political capital, Ur remained a major religious and economic hub. Excavations from this period show continued occupation and temple activity, particularly around the moon-god Nanna's cult. Decline began in the later part of this period as political centers shifted northward and the Euphrates changed course, impacting agriculture and trade.

Late Bronze and Early Iron Ages
During the Late Bronze Age and Early Iron Age (circa 1600–600 BCE) Ur entered a phase of relative obscurity during the Kassite and subsequent Assyrian periods. While still inhabited, its political significance faded. Temples were occasionally restored, especially under the Neo-Assyrian and Neo-Babylonian kings who sought to revive ancient religious centers. Archaeological evidence shows periodic rebuilding and religious pilgrimage, but Ur never regained its former status. By the time of the Neo-Babylonian Empire, the city was marginal within the imperial structure.

Achaemenid and Hellenistic Periods
During this period (circa 539–300s BCE), under Persian rule, Ur saw renewed interest, with the ziggurat and temple complexes maintained or restored, possibly for ideological reasons to legitimize Persian rule in Mesopotamia. However, administrative functions were concentrated in other centers. Greek sources from the Hellenistic period mention Babylon more than Ur, and it appears the city was in decline, though sporadic religious activity may have continued.

Parthian and Sasanian Periods
By the Parthian and subsequent Sasanian periods (circa 300 BCE–300 CE), Ur was largely in ruins. Sparse archaeological remains from this period suggest limited settlement and reuse of older structures. The site retained symbolic importance, but there is no indication of urban revival. By late antiquity, the city was abandoned, buried under centuries of wind-blown sand and forgotten until its rediscovery in the modern period.

circa 2100 BCE

Layout
The city, said to have been planned by Ur-Nammu, was apparently divided into neighbourhoods, with merchants living in one quarter, artisans in another. There were streets both wide and narrow, and open spaces for gatherings. Many structures for water resource management and flood control are in evidence. Houses were constructed from mudbricks and mud plaster. In major buildings, the masonry was strengthened with bitumen and reeds. Ur was surrounded by sloping ramparts 8 metres high and about 25 metres wide.

circa 2100 BCE

Temenos Precinct
The Temenos of Ur, also known as the "Sacred Precinct" or the "Royal Precinct", was a walled area located a little to the north-west of the city center. It consisted of royal and religious buildings, including the Ziggurat, Nanna Court, Boat Shrine, Giparu (Nin-Gal shrine), Dub-Lal-Mah (the gateway shrine to the ziggurat), Palace of Ur-Nammu (Ekhursag).

circa 2100 BCE

Great Ziggurat
The Great Ziggurat, the larget part of temple complex was dedicated to moon god Nanna. Originally built in 2100 BCE by the King Ur-Nammu who dedicated it in honour of Nanna/Sîn and then rebuilt in 600 BCE by Nabonidus and was dedicated to moon god Nanna. The remains of the ziggurat consist of a three-layered solid mass of mud brick faced with burnt bricks set in bitumen.

circa 2100 BCE

House of Abraham
The so-called "House of Abraham" or the "House of Prophet Ibrahim", is a reconstructed structure in the archaeological site of ancient Ur at the modern day site of Tell al-Muqayyar. It is situated approx. 500 meters south-east of the Great Ziggurat of Ur. It was designated as the "House of Abraham" in the early 20th century CE by Christian missionaries and later by some touristic and religious narratives, particularly under Saddam Hussein's regime in the 1990s, as part of a campaign to associate Iraq with biblical heritage. However, this identification is entirely speculative and has no basis in archaeology or historical evidence. The structure was extensively reconstructed during the reign of Saddam Hussein and resembles two roughly triangular shapes joined together.

circa 2600-2400 BCE

Standard of Ur
The so-called Standard of Ur despite its name, the object is not a standard in the military sense but a hollow wooden trapezoidal box, approximately 21.6 centimeters high, 49.5 centimeters long, and 24 centimeters wide. Its surfaces are inlaid with shell, lapis lazuli, and red limestone, forming detailed mosaic panels that provide critical insight into Sumerian social, political, and military life during the Early Dynastic III period.