Adad-nirari III (also Adad-narari) was King of Assyria from 811 to 783 BC. He was the son and successor of Shamshi-Adad V, and was apparently quite young at the time of his accession, because for the first five years of his reign his mother Shammuramat acted as regent, which may have given rise to the legend of Semiramis.
Adad-nirari's youth, and the struggles his father had faced early in his reign, caused a serious weakening for the Assyrian rulership over Mesopotamia, and gave way to the ambitions of the most high officers, the governors and the local rulers.
According to Adad-nirari's inscriptions, he led several military campaigns with the purpose of regaining the strength Assyria enjoyed in the times of his grandfather, Shalmaneser III. According to the eponym canon, he campaigned in all directions until the last of his 28 years of reign, and he was the builder of the temple of Nabu at Nineveh. Among his actions was a siege of Damascus in the time of Ben-Hadad III in 796 BCE, which led to the eclipse of the Aramaean Kingdom of Damascus and allowed the recovery of Israel under Jehoash (who paid the Assyrian king tribute at this time) and Jeroboam II. Additionally, he is thought by some to be the "King of Nineveh" who, upon receiving Jonah's prophecy of forthcoming doom, dressed himself in sackcloth and ordered a fast throughout the city in a successful attempt to prevent it. (Jonah 3:6–9)
In spite of Adad-nirari's vigor, Assyria entered a several decades long period of weakness following his death.