They had been steadily growing in power, and had intermarried into the royal family of Babylonia.

Assur-yuballidh, one of whose letters to the Pharaoh has been found at Tel el-Amarna, had married his daughter to the uncle and predecessor of Burna-buryas, and his grandson became king of Babylon.

A revolt on the part of the Kassite troops gave the Assyrians an excuse for interfering in the affairs of Babylonia, and from this time forward their eyes were turned covetously towards the kingdom of the south.
As Assyria grew stronger, Babylonia became weaker.

Calah, now _Nimrud_, was founded about B.C.1300 by Shalmaneser I., and his son and successor Tiglath-Ninip threw off all disguise and marched boldly into Babylonia in the fifth year of his reign.

Babylon was taken, the treasures of its temple sent to Assur, and Assyrian governors set over the country, while a special seal was made for the use of the conqueror.