Nineveh (modern-day Mosul, Iraq) was one of the oldest and greatest cities in antiquity.
The area was settled as early as 6000 BCE and, by 3000, had become an important religious centre for worship of the goddess Ishtar. The early city (and subsequent buildings) were constructed on a fault line and, consequently, suffered damage from a number of earthquakes. One such event destroyed the first temple of Ishtar which was then rebuilt in 2260 BCE by the Akkadian king Manishtusu.
The Amorites occupied the site and one of their kings, Shamshi-Addu I, added to the temple and left behind inscriptions recording his other construction projects. King Shalmaneser I (reigned 1274-1245 and also constructed the city of Kalhu), built a palace and temple there and is thought to be responsible also for the first walls surrounding the settlement.

The city grew dramatically in size, grandeur and fame, however, under the reign of King Sennacherib (704 - 681) who made Nineveh capital of his Assyrian Empire. Sennacherib was the son of King Sargon II who was killed in battle (a death considered shameful because it was believed that such a death was a punishment from the gods for one's sins) and the new ruler wished to distance himself as much as possible from his father. Sennacherib abandoned Sargon II's new capital city of Dur-Sharrukin and moved it to Nineveh early in his reign. Anything which could be moved from Dur-Sharrukin was relocated to Nineveh. He built great walls around the city with fifteen gates, created public parks and gardens, aqueducts, irrigation ditches, canals, and greatly expanded upon and improved the structures of the city. His palace had eighty rooms and he proclaimed it "the palace without rival" (the same phrase used by his father to describe his own palace at Dur-Sharrukin).

The historian Gwendolyn Leick notes, "Nineveh, with its heterogeneous population of people from throughout the Assyrian Empire, was one of the most beautiful cities in the Near East, with its gardens, temples, and splendid palaces" (132) and further cites Nineveh as having a carefully planned and executed series of canals and aquaducts to ensure a steady supply of water not only for human consumption but also to keep the public parks and gardens irrigated; an aspect of urban life not every city attended to with as much care and planning. Recent scholarship claims that the famous Hanging Gardens of Babylon were actually located at Nineveh and were constructed under Sennacherib's reign.

The historian Christopher Scarre writes: Sennacherib’s palace had all the usual accoutrements of a major Assyrian residence: colossal guardian figures and impressively carved stone reliefs (over 2,000 sculptured slabs in 71 rooms). Its gardens, too, were exceptional.
Recent research by British Assyriologist Stephanie Dalley has suggested that these were the famous Hanging Gardens, one of the Seven Wonders of the Ancient World.
Later writers placed the Hanging Gardens at Babylon, but extensive research has failed to find any trace of them. Sennacherib’s proud account of the palace gardens he created at Nineveh fits that of the Hanging Gardens in several significant details.

After Sennacherib, his son Esarhaddon (reigned 681-669 BCE) took the throne and continued his father's building projects. When Esarhaddon died on campaign in Egypt his mother Zakutu ruled briefly as queen until she legitimized the succession of his son Ashurbanipal as the new king. Under Ashurbanipal's reign (668-627 BCE) a new palace was constructed and he began the process of collecting and cataloging all of the written works in Mesopotamia. The result of his efforts was Ashurbanipal's famous library which held over 30,000 inscribed clay tablets, the books of that time.

Other improvements and renovations were made to the city under Ashurbanipal's reign which further enhanced Nineveh's reputation as a city of extraordinary beauty and high culture. Palaces decorated with enormous and intricate relief paintings were constructed and the public gardens expanded upon and enhanced.
Ashurbanipal's love of learning, and interest in written works, drew scholars and scribes to the city in great numbers and the stability of his reign allowed for the development of the arts, sciences, and architectural innovations.
Ashurbanipal died in 627 BCE and his sons fought for control of the throne.
The Assyrian Empire was so large by this time that maintaining it was almost impossible. The regions which were subject to Assyrian rule had been trying to break free for years and, finally, they saw their chance.
The historian Simon Anglim writes that, "though the Assyrians and their army were respected and feared, they were most of all hated...by the last quarter of the seventh century BCE nearly every part of the empire was in a state of rebellion; these were not just struggles of freedom but wars of revenge" .
Military incursions by the Persians, Babylonians, Medes, and Scythians began in earnest in 625 BCE and the already weakened Neo-Assyrian Empire could not hold off a full-scale invasion for very long. In 612 BCE the city of Nineveh was sacked and burned by the allied forces of the Persians, Medes, Babylonians, and others who then divided the region between them. The area was sparsely populated thereafter and, slowly, the ancient ruins became buried in earth.

exracted from https://www.ancient.eu/nineveh/