The island itself, also, with the fortress at the other end of the pier, was still in the possession of the Egyptian authorities, who seemed disposed to hold it for Achillas.
The mole was very long, as the island was nearly a mile from the shore.
There was quite a little town upon the island itself, besides the fortress or castle built there to defend the place.

The garrison of this castle was strong, and the inhabitants of the town, too, constituted a somewhat formidable population, as they consisted of fishermen, sailors, wreckers, and such other desperate characters, as usually congregate about such a spot.

Cleopatra and Caesar, from the windows of their palace within the city, looked out upon this island, with the tall light house rising in the center of it and the castle at its base, and upon the long and narrow isthmus connecting it with the main land, and concluded that it was very essential that they should get possession of the post, commanding, as it did, the entrance to the harbor.
In the harbor, which was on the south side of the mole, and, consequently, on the side opposite to that from which Achillas was advancing toward the city, there were lying a large number of Egyptian vessels, some dismantled, and others manned and armed more or less effectively.

These vessels had not yet come into Achillas's hands, but it would be certain that he would take possession of them as soon as he should gain admittance to those parts of the city which Caesar had abandoned.

This it was extremely important to prevent; for, if Achillas held this fleet, especially if he continued to command the island of Pharos, he would be perfect master of all the approaches to the city on the side of the sea.