Nineveh, Assyrian Ninua was an important city in ancient Assyria. This "exceeding great city", as it is called in the Book of Jonah, lay on the eastern bank of the Tigris (modern-day Mosul, Iraq). Ancient Nineveh's mound-ruins are located on a level part of the plain near the river within an 1800-acre area circumscribed by a seven and one-half mile brick-rampart. This whole extensive space is now one immense area of ruins. If Jonah is referring to what some scholars call Greater Nineveh, the term could include the region around Nineveh proper with a sixty mile perimeter including Kuyunjik, Khorsabad, and Nimrud.
Situated at the confluence of the Tigris and Khosr, Nineveh was an important junction for commercial routes crossing the Tigris. Occupying a central position on the great highway between the Mediterranean and the Indian Ocean, thus uniting the East and the West, wealth flowed into it from many sources, so that it became one of the greatest of all ancient cities.
6000 BC: First settlements of Nineveh.
2nd and 3rd millennia BC: Nineveh is a religious centre devoted to among other gods Ishtar.
9th century BC: Large architectural projects start in Nineveh with the initiative of rulers of the Assyrian Empire.
705 BC: King Sennacherib establishes Nineveh as the new capital of the Assyrian Empire, at the expense of Dar Sharrukin. Large scale construction work is started, together with the building of the largest palace of its time, which was 42,000 km2 large with at least 80 rooms.
Around 650 BC: Under King Ashurbanipal, a new palace is constructed, together with a large library.

Ashurbanipal - King of Assyria. He was grandson of the famous Sennacherib and son of Esarhaddon. Ashurbanipal, or, as he was known to the Greeks, Sardanapalus, reigned from 668 to 626 B.C. He is best known for amassing a library of literary texts including an epic of creation, the Flood and others. Modern scholars have reason to be grateful to Ashurbanipal because he was a lover of learning and collected a great library of cuneiform clay tablets (over 22,000 in number) that have given to us most of what we know of Babylonian and Assyrian literature. In Ezra 4:10, his name is also rendered "Asnapper" or "Osnapper".
612 BC: Ashurbanipal's successor held the Assyrian throne and at his death Sin-shar-ishkin became king. In the summer of 612, Nabopolassar, a Chaldean leader, aided by Medes and northern nomads, attacked, looted and destroyed Nineveh, an event that marked the crumbling of the last vestiges of power in Assyria and established the foundations for the Neo-Babylonian Empire. There is some evidence that the defeat of Nineveh was the occasion of rejoicing in Judah, although the Assyrians established a new capital at Harran. Within a few years Harran was conquered by the Medes.
13th century AD: Nineveh becomes an important city under Atabeg rulers.
16the century: The last settlements of Nineveh are abandoned.
1820: Nineveh is mapped by the British archaeologist Claudius J. Rich.
1845-51: The palace of Sennacherib is discovered.
Temple
Royal Palace
Nineveh is mentioned about 1800 BC as a worship place of Isatar, who was responsible for the city's early importance. There is no large body of evidence to show that Assyrian monarchs built at all extensively in Nineveh during the 2nd millennium BC. When Sennacherib made Ninua his capital at the end of the 8th century BC, it was already an ancient settlement. Later monarchs whose inscriptions have appeared on the Acropolis include Shalmaneser I and Tiglath-Pileser I, both of whom were active builders in Asshur; the former had founded Calah (Nimrud). Nineveh had to wait for the neo-Assyrians, particularly from the time of Ashurnasirpal II (ruled 883-859 BC) onward, for a considerable architectural expansion. Thereafter successive monarchs kept in repair and founded new palaces, temples to Sin, Nergal, Nanna, Samas, Isatar, and Nabiu of Borsippa.

Interior of Sennacherib's Palace

It was Sennacherib who made Nineveh a truly magnificent city (c. 700 BC). He laid out fresh streets and squares and built within it the famous "palace without a rival", the plan of which has been mostly recovered and has overall dimensions of about 210 by 200 m (630 by 600 ft). It comprised at least 80 rooms, of which many were lined with sculpture.
Nineveh's greatness was short-lived. About 633 BC the Assyrian empire began to show signs of weakness, and Nineveh was attacked by the Medes, who subsequently, about 625 BC, joined by the Babylonians and Susianians, again attacked it.
Nineveh fell in 612 BC, and was razed to the ground. The Assyrian empire then came to an end, the Medes and Babylonians dividing its provinces between them.
Following the defeat in 612 BC, Nineveh fades in importance. The city is mentioned again in the Battle of Nineveh in 627 CE, which was fought between the Eastern Roman Empire and the Sassanian Empire of Persia near the ancient city.
Before the excavations in the 1800s, our knowledge of the great Assyrian empire and of its magnificent capital was almost wholly a blank. Vague memories had indeed survived of its power and greatness, but very little was definitely known about it.
Other cities which had perished, such as Palmyra, Persepolis, and Thebes, had left ruins to mark their sites and tell of their former greatness; but of this city, imperial Nineveh, not a single vestige seemed to remain, and the very place on which it had stood was only matter of conjecture.In the days of the Greek historian Herodotus, 400 BC, it had become a thing of the past; and when Xenophon the historian passed the place in the Retreat of the Ten Thousand the very memory of its name had been lost. It was buried out of sight.