The empire of Seleucus might have been conveniently ruled from the site of the ancient Nineveh, or from either of the two still existing and still flourishing cities of Susa and Babylon.

The impetus given to commerce by the circumstances of the time rendered a site near the sea preferable to one so remote as that of Nineveh, and the same consideration made a position on the Tigris or Euphrates more advantageous than one upon a smaller river.

So far, all pointed to Babylon as the natural and best metropolis; and it was further in favor of that place that its merits had struck the Great Conqueror, who had designed to make it the capital of his own still vaster Empire.
Accordingly Babylon was Seleucus's first choice; and there his Court was held for some years previously to his march against Antigonus.
But either certain disadvantages were found to attach to Babylon as a residence, or the mere love of variety and change caused him very shortly to repent of his selection, and to transfer his capital to another site.

He founded, and built with great rapidity, the city of Seleucia upon the Tigris, at the distance of about forty miles from Babylon, and had transferred thither the seat of government even before B.C.301.

Thus far, however, no fault had been committed.