The Assyrian king Shalmaneser I (1274–1245 BCE) founded or built up Kalḫu into a major city during the Middle Assyrian Empire (1365–1050 BCE). However, the ancient city of Aššur remained the capital of Assyria, as it had been since circa 2600 BCE.

It became the capital of the Assyrian Empire under the reign of Ashurnasirpal II (883–859 BCE). The city reached its peak during the 9th and 8th centuries BCE and was known for its impressive architecture, including palaces, temples, and fortifications.

The city of Nimrud was eventually abandoned, and its ruins were rediscovered by archaeologists in the nineteenth century CE. Unfortunately, in recent years, Nimrud has suffered significant damage and destruction due to the Syrian civil war and vandalism, leading to the loss of some of its invaluable historical and cultural heritage.

circa 858–823 BCE

Nimrud Ziggurat
Also known as the "Kalhu Ziggurat" the temple-tower of the god Ninurta, which was started by the ninth century BCE Assyrian ruler Ashurnasirpal II (reigned 883–859 BCE) and completed by his son and successor Shalmaneser III (reigned 858–824 BCE), was the most prominent feature of Kalhu (modern Nimrud) until its destruction during the Syrian civil war around mid-2015 CE. This multi-staged ziggurat, whose remains were a pyramid of eroding mud-brick, was constructed in the northwest corner of the citadel, next to Kalhu's principal sanctuary, the Ninurta temple.

circa 865 BCE

North-West Palace of AshurNasirPal II
An impressive and ornately-decorated palace constructed at Kalḫu (modern Nimrud, biblical Calah) by the ninth century BCE Assyrian ruler Ashurnasirpal II (reigned 883–859 BCE), likely completed between 865 and 869 BCE. This multi-winged palatial complex served as the primary residence and chief administrative center of the Assyrian Empire until Sargon II (reigned 721–705 BCE) moved the imperial capital to Dūr-Šarrukīn in 706 BCE. The Northwest Palace, the name given to it by its excavators (since it was built in the northwestern part of Kalḫu’s citadel or acropolis), remained in use until the very end of the Assyrian Empire (612 BCE). The southern half of the building also functioned as the burial place of prominent royal women, including Mullissu-mukannišat-Ninua, the wife of Ashurnasirpal and the mother of Shalmaneser III.

The detailed carved reliefs on display at the British Museum and other museum around the world originally stood in the palace throne-room and in other royal apartments. They depict the king and his subjects engaged in a variety of activities. Ashurnasirpal is shown leading military campaigns against his enemies, engaging in ritual scenes with protective demons and hunting, a royal sport in ancient Mesopotamia.

One of the most famous structures in Nimrud was the Northwest Palace, built by Ashurnasirpal II. The palace was adorned with intricate relief carvings depicting scenes of royal rituals, hunting, and warfare. These reliefs provided valuable insights into the art, culture, and daily life of the ancient Assyrians.

circa 800 BCE

Temple of Nabu and Tashmetu
The Temple of Nabu and his consort Tashmetu was first constructed about 800 BCE and then remained essentially unchanged for the next hundred years or so. Just before 700 BCE much of the northern part of the temple was built anew, and perhaps completely remodelled. It is essentially this version of Ezida (the temple precinct) that was used right until the end of empire and which excavators discovered in the nineteenth and twentieth centuries. Unlike most of the religious buildings constructed at Kalhu, the Ezida ("True House") was built in the southeast corner of the Citadel.

The Nabû temple was one of the nine temples that the ninth-century-BCE Assyrian king Ashurnasirpal II claims to have (re)founded when he made Kalhu his primary royal residence; Ezida, a name that was adopted from this deity’s temple in Borsippa (Birs Nimrud), is situated on the southeast side of the citadel mound. The building plan consists of two large courtyards on the east, the shrines themselves facing onto the inner court; there are also two smaller courtyards, a twin set of shrines, and a reception suite ("Throne Room") in the northwest quarter of the building ("South-East Building" or SEB). The entire southern part of the temple was rebuilt by Adad-Nārārī III, to whom the seventh-century rulers Ashurbanipal and Sîn-šarru-iškun attribute its foundation (or at least its last rebuilding).

Little is known about Adad-nārārī III’s work on Ezida from the textual record, but his inscriptions were found on a slab in the main shrine and on colossal statues with folded hands, presumably divine attendants of the god. In addition, Bēl-tarṣi-ilūma, the governor of Kalhu, dedicated two further statues (also attendants) for the life of Adad-nārārī and his mother Sammu-ramat (Semiramis). Adad-nārārī appears to have (re)built the southern wing of the temple, although the original version of the temple (the northern section) was almost certainly nineth century BCE in date (reign of Ashurnasirpal II).

circa 865-860 BCE

Victory Relief
The wall panel, carved from gypsum, originating from AshurNasirPal II's north-west palace in Kalhu (bblical Calah), Assyria, dates back to circa 865-860 BCE. The meticulously carved panel depicts the Assyrian king, AshurNasirPal II, returning triumphantly from war in his chariot. one attendant within the chariot holds a parasol over him, while another guides his horses. Positioned behind the chariot is a horseman with spare steeds, accompanied by two soldiers armed with bows and maces. Above the horses, the emblem (inspect) of the god Assur is depicted, and lifeless bodies can be seen along the roadside. This masterpiece also features an inscription in cuneiform script, highlighting the remarkable craftsmanship of ancient Assyrian artists from that era. It is indeed fitting that Mesopotamia is often called the cradel of civilization. The wall panel was discovered by the British archaeologists Austen Henry Layard in 1846 CE, and is currently displayed at the British Museum in London.

• Wall Panel; Relief, British Museum, London (1849,1222.12)

circa 865-860 BCE

Relief of Retreating Enemy Swimmers
Gypsum wall panel with a complete composition in relief: two Assyrian archers are shooting at the enemy; they are dressed and armed as typical Assyrian soldiers, with pointed helmets, short kilts, swords and bows, and with quivers on their backs. Two of the trees growing on the bank are crudely drawn and hardly identifyable, but the third is unmistakably a date-palm. There are three enemies in the water: their long robes indicate that they are all people of high status rather than ordinary soldiers. One is swimming, and has been hit by arrows. The other two are using inflated animal-skins to help support themselves in the water, blowing into them as they struggle towards the fort on the right. The one without a beard is probably a eunuch.

The foundations of the fort, which may be on an island, appear to be of stone, whereas the walls themselves would probably have been mud-brick. The arched shape of the doors is typical of the period.

There are traces of the standard inscription at the bottom of the panel.

This panel probably shows an incident described in Ashurnasirpal's annals. In 878 BC the king was campaigning down the Euphrates river, and reached the enemy capital a little south-east of the modern town of Ana. Then, 'in the face of the mighty weapons, Kudurru with seventy of his soldiers fell back into the Euphrates to save his life' (Grayson, 1976: 138).

• Wall Panel; Relief, British Museum, London (1849,1222.10)