Instead, however, of endeavoring to promote a settlement of the quarrel with Caesar, he seemed to enter into it now himself, personally, with the utmost ardor, and began at once to make the most extensive preparations both by sea and land for a vigorous prosecution of the war.

What the result of these operations would have been can now not be known, for the general aspect of affairs was, soon after these transactions, totally changed by the occurrence of a new and very important event which suddenly intervened, and which turned the attention of all parties, both Egyptians and Romans, to the eastern quarter of the kingdom.

The tidings arrived that a large army under the command of a general named Mithradates, whom Caesar had dispatched into Asia for this purpose, had suddenly appeared at Pelusium, had captured that city and were now ready to march to Alexandria.
The Egyptian army immediately broke up its encampments in the neighborhood of Alexandria, and marched to the eastward to meet these new invaders, Caesar followed them with all the forces that he could safely take away from the city.

He left the city in the night, and unobserved, and moved across the country with such celerity that he joined Mithradates before the forces of Ptolemy had arrived.

After various marches and maneuvers, the armies met, and a great battle was fought.