Nippur in the context of Logogram

The Babylonian calendar was a lunisolar calendar used in Mesopotamia from around the 2nd millennium BC until the Seleucid Era (294 BC), and it was specifically used in Babylon from the Old Babylonian Period (1780s BC) until the Seleucid Era.

In the Seleucid Era it was reformed as "Greek time", Anno Graecorum was introduced and used in the Middle East and Egypt until the middle of the first millennium when the First Council of Nicaea AD 325 defined the Church year based on the Roman early Julian calendar. As Anno Graecorum formed the basis for time references in the Bible and spread westward, it rather increased the Babylonian calendars importance. The Babylonian calendar is also partly reflected in calendars in South and East Asia and the Islamic calendar as well as Iranian calendars. The Julian calendar inherited the definitions of the 12 month system, week, hour etc. from the Babylonian calendar and the current Jewish calendar can be seen as a slightly modified Babylonian calendar that still exists today and is practised, but with Anno Mundi Livryat haOlam year calculation since the creation of the world. Today's global time system UTC (Gregorian calendar) therefore has its main structure inherited from the Babylonian calendar.

Uruk, the archeological site known today as Warka, was an ancient city in the Near East or West Asia, located east of the current bed of the Euphrates River, on an ancient, now-dried channel of the river in Muthanna Governorate, Iraq. The site lies 93 kilometers (58 miles) northwest of ancient Ur, 108 kilometers (67 miles) southeast of ancient Nippur, and 24 kilometers (15 miles) northwest of ancient Larsa. It is 30 km (19 mi) east of modern Samawah.

Uruk is the type site for the Uruk period. Uruk played a leading role in the early urbanization of Sumer in the mid-4th millennium BC.By the final phase of the Uruk period around 3100 BC, the city may have had 40,000 residents, with 80,000–90,000 people living in its environs, making it the largest urban area in the world at the time. Gilgamesh, according to the chronology presented in the Sumerian King List (SKL), ruled Uruk in the 27th century BC. After the end of the Early Dynastic period, with the rise of the Akkadian Empire, the city lost its prime importance. It had periods of florescence during the Isin-Larsa period, Neo-Assyrian and Neo-Babylonian periods and throughout the Achaemenid (550–330 BC), Seleucid (312–63 BC) and Parthian (227 BC to AD 224) periods, until it was finally abandoned shortly before or after the Islamic conquest of 633–638.

Ninshubur (𒀭𒎏𒋚,; Ninšubur, "Lady of Subartu" or "Lady of servants"), also spelled Ninšubura, was a Mesopotamian goddess regarded as the sukkal (divine attendant) of the goddess Inanna. While it is agreed that in this context Ninshubur was regarded as female, in other cases the deity was considered male, possibly due to syncretism with other divine messengers, such as Ilabrat. No certain information about her genealogy is present in any known sources, and she was typically regarded as unmarried. As a sukkal, she functioned both as a messenger deity and as an intercessor between other members of the pantheon and human petitioners.

Due to the belief that she could intercede with higher ranking deities, Ninshubur was popular in everyday religion, and many theophoric names invoking her and other references to personal worship are known. Her original cult center was Akkil, but in the Early Dynastic Period she was already worshiped in nearby Uruk. She was also introduced to the pantheon of the state of Lagash, where her cult center was Girsu. Multiple kings of this area regarded her as their personal deity. In the Ur III period she was also introduced to Ur. Further cities where Ninshubur was worshiped include Adab, Nippur, Malgium, and more.

The Early Dynastic Period (abbreviated ED Period or ED) is an archaeological culture in Mesopotamia (modern-day Iraq) that is generally dated to c. 2900 – c. 2350 BC and was preceded by the Uruk and Jemdet Nasr periods. It saw the development of writing and the formation of the first cities and states. The ED itself was characterized by the existence of multiple city-states: small states with a relatively simple structure that developed and solidified over time. This development ultimately led, directly after this period, to broad Mesopotamian unification under the rule of Sargon, the first monarch of the Akkadian Empire. Despite their political fragmentation, the ED city-states shared a relatively homogeneous material culture. Sumerian cities such as Uruk, Ur, Lagash, Umma, and Nippur located in Lower Mesopotamia were very powerful and influential. To the north and west stretched states centered on cities such as Kish, Mari, Nagar, and Ebla.

The study of Central and Lower Mesopotamia has long been given priority over neighboring regions. Archaeological sites in Central and Lower Mesopotamia—notably Girsu but also Eshnunna, Khafajah, Ur, and many others—have been excavated since the 19th century. These excavations have yielded cuneiform texts and many other important artifacts. As a result, this area was better known than neighboring regions, but the excavation and publication of the archives of Ebla have changed this perspective by shedding more light on surrounding areas, such as Upper Mesopotamia, western Syria, and southwestern Iran. These new findings revealed that Lower Mesopotamia shared many socio-cultural developments with neighboring areas and that the entirety of the ancient Near East participated in an exchange network in which material goods and ideas were being circulated.

Ninurta (Sumerian: 𒀭𒊩𒌆𒅁: NIN.URTA, possible meaning "Lord [of] Barley"), also known as Ninĝirsu (Sumerian: 𒀭𒊩𒌆𒄈𒋢: NIN.ĜIR₂.SU, meaning "Lord [of] Girsu"), is an ancient Mesopotamian god associated with farming, healing, hunting, law, scribes, and war who was first worshipped in early Sumer. In the earliest records, he is a god of agriculture and healing, who cures humans of sicknesses and releases them from the power of demons. In later times, as Mesopotamia grew more militarized, he became a warrior deity, though he retained many of his earlier agricultural attributes. He was regarded as the son of the chief god Enlil and his main cult center in Sumer was the Eshumesha temple in Nippur. Ninĝirsu was honored by King Gudea of Lagash (ruled 2144–2124 BC), who rebuilt Ninĝirsu's temple in Lagash. Later, Ninurta became beloved by the Assyrians as a formidable warrior. The Assyrian king Ashurnasirpal II (ruled 883–859 BC) built a massive temple for him at Kalhu, which became his most important cult center from then on.

In the epic poem Lugal-e, Ninurta slays the demon Asag using his talking mace Sharur and uses stones to build the Tigris and Euphrates rivers to make them useful for irrigation. In a poem sometimes referred to as the "Sumerian Georgica", Ninurta provides agricultural advice to farmers. In an Akkadian myth, he was the champion of the gods against the Anzû bird after it stole the Tablet of Destinies from his father Enlil and, in a myth that is alluded to in many works but never fully preserved, he killed a group of warriors known as the "Slain Heroes". His major symbols were a perched bird and a plow.

Enlil, later known as Elil and Ellil, is an ancient Mesopotamian god associated with wind, air, earth, and storms. He is first attested as the chief deity of the Sumerian pantheon, but he was later worshipped by the Akkadians, Babylonians, Assyrians, and Hurrians. Enlil's primary center of worship was the Ekur temple in the city of Nippur, which was believed to have been built by Enlil himself and was regarded as the "mooring-rope" of heaven and earth. He is also sometimes referred to in Sumerian texts as Nunamnir. According to one Sumerian hymn, Enlil himself was so holy that not even the other gods could look upon him. Enlil rose to prominence during the twenty-fourth century BC with the rise of Nippur. His cult fell into decline after Nippur was sacked by the Elamites in 1230 BC and he was eventually supplanted as the chief god of the Mesopotamian pantheon by the Babylonian national god Marduk.

Enlil plays a vital role in the ancient near eastern cosmology; he separates An (heaven) from Ki (earth), thus making the world habitable for humans. In the Sumerian flood myth Eridu Genesis, Enlil rewards Ziusudra with immortality for having survived the flood and, in the Babylonian flood myth, Enlil is the cause of the flood himself, having sent the flood to exterminate the human race, who made too much noise and prevented him from sleeping; the cuneiform tablets of Atra-Hasis report on this connections in a comparatively well-preserved state. The myth of Enlil and Ninlil is about Enlil's serial seduction of the goddess Ninlil in various guises, resulting in the conception of the moon-god Nanna and the Underworld deities Nergal, Ninazu, and Enbilulu. Enlil was regarded as the inventor of the mattock and the patron of agriculture. Enlil also features prominently in several myths involving his son Ninurta, including Anzû and the Tablet of Destinies and Lugale.

Ninsun (also called Ninsumun, cuneiform: 𒀭𒊩𒌆𒄢 NIN.SUMUN_2; Sumerian: Nin-sumun(ak) "lady of the wild cows") was a Mesopotamian goddess. She is best known as the mother of the hero Gilgamesh and wife of deified legendary king Lugalbanda, and appears in this role in most versions of the Epic of Gilgamesh. She was associated with Uruk, where she lives in this composition, but she was also worshiped in other cities of ancient Mesopotamia, such as Nippur and Ur, and her main cult center was the settlement KI.KAL.

The degree of Ninsun's involvement in Gilgamesh's life varies between various versions of the Epic. She only plays an active role in the so-called "Standard Babylonian" version, in which she advises her son and interprets his dreams, petitions the sun god Shamash to protect him, and accepts Enkidu as a member of her family. In the Old Babylonian version her role is passive, with her actions being merely briefly discussed by Shamhat, while a Hittite translation of the text omits her altogether. She is additionally present in older Sumerian compositions, including Gilgamesh and the Bull of Heaven, as well as a poorly preserved and very early myth describing her first meeting with Lugalbanda and their marriage.

A pointed arch, ogival arch, or Gothic arch is an arch with a pointed crown, whose two curving sides meet at a relatively sharp angle at the top of the arch. Also known as a two-centred arch, its form is derived from the intersection of two circles. This architectural element was particularly important in Gothic architecture. The earliest use of a pointed arch dates back to bronze-age Nippur. As a structural feature, it was first used in eastern Christian architecture, Byzantine architecture and Sasanian architecture, but in the 12th century it came into use in France and England as an important structural element, in combination with other elements, such as the rib vault and later the flying buttress. These allowed the construction of cathedrals, palaces and other buildings with dramatically greater height and larger windows which filled them with light.

Shuruppak (Sumerian: 𒋢𒆳𒊒𒆠 Šuruppag, SU.KUR.RU, "the healing place"), modern Tell Fara, was an ancient Sumerian city situated about 55 kilometres (35 mi) south of Nippur and 30 kilometers north of ancient Uruk on the banks of the Euphrates in Iraq's Al-Qādisiyyah Governorate. Shuruppak was dedicated to Ninlil, also called Sud, the goddess of grain and the air. The Early Dynastic IIIa period is also sometimes called the Fara period. Not to be confused with the Levantine archaeological site Tell el-Far'ah (South).

"Shuruppak" is sometimes also the name of a king of the city, legendary survivor of the Flood, and supposed author of the Instructions of Shuruppak".

Ancient Mesopotamian units of measurement originated in the loosely organized city-states of Early Dynastic Sumer. Each city, kingdom and trade guild had its own standards until the formation of the Akkadian Empire when Sargon of Akkad issued a common standard. This standard was improved by Naram-Sin, but fell into disuse after the Akkadian Empire dissolved. The standard of Naram-Sin was readopted in the Ur III period by the Nanše Hymn which reduced a plethora of multiple standards to a few agreed-upon common groupings. Successors to Sumerian civilization including the Babylonians, Assyrians, and Persians continued to use these groupings. Akkado-Sumerian metrology has been reconstructed by applying statistical methods to compare Sumerian architecture, architectural plans, and issued official standards such as Statue B of Gudea and the bronze cubit of Nippur.

Lumma was a Mesopotamian god who could be portrayed as a warrior or as a farmer. It has been proposed that he was originally understood as the deified form of historical king Eannatum of Lagash, but this theory remains a matter of dispute among researchers. He could be paired with Ḫadaniš, and together they belonged to the group of deities associated with Enlil and the temple Ekur. The goddess Ninmug could be described as his mother. The worship of Lumma is best documented in Umma and Nippur. One of the kings of the former of these two cities bore the theophoric name Ur-Lumma.

Khafajah or Khafaje (Arabic: خفاجة), ancient Tutub, is an archaeological site in Diyala Governorate, Iraq 7 miles (11 km) east of Baghdad. Khafajah lies on the Diyala River, a tributary of the Tigris. Occupied from the Uruk and Jemdet Nasr periods through the end of the Old Babylonian Empire, it was under the control of the Akkadian Empire and then the Third Dynasty of Ur in the 3rd millennium BC. It then became part of the empire of the city-state of Eshnunna lying 12 miles (19 km) southwest of that city, about 5 miles (8.0 km) from the ancient city of Shaduppum, and near Tell Ishchali, both of which Eshnunna also controlled. It then fell to First Babylonian Empire before falling into disuse. The city of Tutub is mentioned in a fragmentary Sumerian temple hymn "... To the shrine Nippur, to the Duranki <we go>, To ..., to the brickwork of Tutub <we go>, To the lofty Abzu ...".

The site of Tulul Khattab (also Telul Khattab) lies 13 kilometers away and at over 50 hectares is one of the largest in the area. The site consists of 14 sub-mounds and it was excavated in 1979 (as it was being exploited by brickmaking industries) recovering 379 Old Babylonian period cuneiform tablets and fragments (225 on Mound 1 and 154 on Mound 2), which featured nine year names of Eshnunna rulers including "Year 2 of Ṣillī-Sîn as king". Only a handful of the tablets have been published.

Ninlil (𒀭𒎏𒆤 NIN.LÍL; meaning uncertain) was a Mesopotamian goddess regarded as the wife of Enlil. She shared many of his functions, especially the responsibility for declaring destinies, and like him was regarded as a senior deity and head of the pantheon. She is also well attested as the mother of his children, such as the underworld god Nergal, the moon god Nanna or the warrior god Ninurta. She was chiefly worshiped in Nippur and nearby Tummal alongside Enlil, and multiple temples and shrines dedicated to her are attested in textual sources from these cities. In the first millennium BCE she was also introduced to Ḫursaĝkalamma near Kish, where she was worshiped alongside the goddess Bizilla, who was likely her sukkal (attendant deity).

At an early date Ninlil was identified with the goddess Sud from Shuruppak, like her associated with Enlil, and eventually fully absorbed her. In the myth Enlil and Sud, Ninlil is the name Sud received after marrying Enlil. Nisaba, the goddess of writing, and her husband Haya are described as her parents. While Ninlil's mother bears a different name, Nunbaršegunu, in the myth Enlil and Ninlil, the god list An = Anum states that it was an alternate name of Nisaba. Syncretism with Sud also resulted in Ninlil acquiring some of her unique characteristics, such as an association with healing goddesses and with Sudaĝ, a name of the wife of the sun god Shamash. References to these connections can be found in various Mesopotamian texts, such as a hymn referring to Ninlil as a healing goddess or a myth apparently confusing her with Sudaĝ in the role of mother of Ishum.

Uraš (Sumerian: 𒀭𒅁, romanized: Uraš), or Urash, was a Mesopotamian goddess regarded as the personification of the earth. She should not be confused with a male deity sharing the same name, who had agricultural character and was worshiped in Dilbat. She is well attested in association with Anu, most commonly as his spouse, though traditions according to which she was one of his ancestors or even his alternate name are also known. She could be equated with other goddesses who could be considered his wives, namely Ki and Antu, though they were not always regarded as identical. Numerous deities were regarded as children of Urash and Anu, for example Ninisina and Ishkur. However, in some cases multiple genealogies existed, for example Enki was usually regarded as the son of Nammu and Geshtinanna of Duttur, even though texts describing them as children of Urash exist. Not much evidence for the worship of Urash is available, though offerings to her are mentioned in documents from the Ur III period and it is possible she had a temple in Nippur.

Adab (Sumerian: 𒌓𒉣𒆠 Adab, spelled UD.NUN) was an ancient Sumerian city between Girsu and Nippur, lying about 35 kilometers (22 miles) southeast of the latter. It was located at the site of modern Bismaya or Bismya in the Al-Qādisiyyah Governorate of Iraq. The site was occupied at least as early as the 3rd millennium BC, through the Early Dynastic, Akkadian Empire, and Ur III Empire periods, into the Kassite period in the mid-2nd millennium BC. It is known that there were temples of Ninhursag/Digirmah, Iskur, Asgi, Inanna and Enki at Adab and that the city-god of Adab was Parag'ellilegarra (Panigingarra) "The Sovereign Appointed by Enlil".

Bismaya is not to be confused with the small, later (Old Babylonian and Sassanian periods) archaeological site named Tell Bismaya, 9 kilometers (5.6 miles) east of the confluence of the Diyala and the Tigris rivers, excavated by Iraqi archaeologists in the 1980s or Tell Basmaya, southeast of modern Baghdad, excavated by Iraqi archaeologists in 2013-2014.

Erridupizir (Erridu-pizir) (fl. 2141–2138 BC (Short chronology)) was a Gutian ruler in Sumer. His reign was attested by a royal inscription at the archaeological site for the ancient city-state of Nippur where he called himself: "King of Guti, King of the Four Quarters" Thought to be the "king without a name" on the SKL. Imta then succeeded Erridupizir.

After the Akkadian Empire fell to the Gutians, the Lullubians rebelled against Erridupizir, according to the latter's inscriptions:

Nuska or Nusku, possibly also known as Našuḫ, was a Mesopotamian god best attested as the sukkal (divine vizier) of Enlil. He was also associated with fire and light, and could be invoked as a protective deity against various demons, such as Lamashtu or gallu. His symbols included a staff, a lamp and a rooster. Various traditions existed regarding his genealogy, with some of them restricted to texts from specific cities. His wife was the goddess Sadarnunna, whose character is poorly known. He could be associated with the fire god Gibil, as well as with various courtiers of Enlil, such as Shuzianna and Ninimma.

The main cult center of Nuska was Nippur, where he is already attested in the Early Dynastic period. He was worshiped both in temples of his own and in the Ekur complex. He is attested in various documents from the Kassite period, including oath formulas and inscriptions, as well as in theophoric names. In later periods, he was introduced to the local pantheons of other cities, including Babylon, Ur and Uruk in the south and Assur and Harran in the north. The last of these cities might have served as his main cult center in the late first millennium BCE. Some attestations of the worship of Nuska are available from outside Mesopotamia, including inscriptions from Chogha Zanbil in Elam and Aramaic documents from Elephantine in Egypt.