Once Egypt was captured, Esarhaddon and his successor, Assurbanipal (680-626 B.C.E.), ruled an empire that stretched over 1,000 miles from the Nile River to the Caucasus Mountains. In its time, the Assyrian Empire was the greatest the world had ever seen.
& 744 BC When did they reach it - They reached their peak under the rule of King Tiglath-Pileser I. The last and most likely strongest, of the Assyrian Empires had ruled from 744 BC to 612 BC. During this time Assyria had a string of powerful and capable rulers such as Tiglath-Pileser III, Sargon II, Sennacherib, and Ashurbanipal.