While the ruins of Calah were remarkably rich in monumental material, enamelled bricks, bronze and ivory objects and the like, they yielded few of the inscribed clay tablets found in such great numbers at Nineveh and various Babylonian sites.
In 746 B.C. Calah joined the rebels, and on the 13th of Iyyar in the following year, Pulu or Pul, who took the name of Tiglath-pileser III., seized the crown and inaugurated a new and vigorous policy.
With the exception of Assur, the original capital, the chief cities of the country, Nineveh, Calah and Arbela, were all on the left bank of the Tigris.
The means at his disposal were inadequate, his excavations were incomplete and also unscientific in that his prime object was the discovery of inscriptions and museum objects; but he was wonderfully successful in achieving the results at which he aimed, and the numerous statues, monuments, inscribed stones, bronze objects and the like found by him in the ruins of Calah are among the most precious possessions of the British Museum.
Not a few of the astrological and omen tablets in the Kuyunjik collection of the British Museum, however, although found at Nineveh, were executed, according to their own testimony, at Calah for the rab-dup-sarre or principal librarian during the reigns of Sargon and Sennacherib (716-684 B.C.).
It remained the capital long after the Assyrians had become the dominant power in western Asia, but was finally supplanted by Calah (Nimrud), Nineveh (Nebi Yunus and Kuyunjik), and Dur-Sargina (Khorsabad), some 60 m.