Calah
    one of the most ancient cities of Assyria. "Out of that land he
    [i.e., Nimrod] went forth into Assyria, and built Nineveh,
    Rehoboth-Ir, and Calah, and Resen" (Gen. 10:11, R.V.). Its site
    is now marked probably by the Nimrud ruins on the left bank of
    the Tigris. These cover an area of about 1,000 acres, and are
    second only in size and importance to the mass of ruins opposite
    Mosul. This city was at one time the capital of the empire, and
    was the residence of Sardanapalus and his successors down to the
    time of Sargon, who built a new capital, the modern Khorsabad.
    It has been conjectured that these four cities mentioned in Gen.
    10:11 were afterwards all united into one and called Nineveh
    (q.v.).
 Calah, favorable; opportunity