The parade of exact dates with reference to very early times is generally fallacious, unless it be understood as adopted simply for the sake of convenience.

In the history of Assyria, however, we may make a nearer approach to exactness than in most others of the same antiquity, owing to the existence of two chronological documents of first-rate importance.

One of these is the famous Canon of Ptolemy, which, though it is directly a Babylonian record, has important bearings on the chronology of Assyria.

The other is an Assyrian Canon, discovered and edited by Sir H.Rawlinson in 1862, which gives the succession of the kings for 251 years, commencing (as is thought) B.C.
911 and terminating B.C.660, eight years after the accession of the son and successor of Esarhaddon.

These two documents, which harmonize admirably, carry up an exact Assyrian chronology almost from the close of the Empire to the tenth century before our era.