It was absolutely necessary to make an attempt to recover the lighthouse-island. The double attack, which was made by boats from the side of the harbour and by the war-vessels from the seaboard, in reality brought not only the island but also the lower part of the mole into his power; it was only at the second arch-opening of the mole that Caesar ordered the attack to be stopped, and the mole to be there closed towards the city by a transverse wall. But while a violent conflict arose here round the entrenchers, the Roman troops left the lower part of the mole adjoining the island bare of defenders; a division of Egyptians landed there unexpectedly, attacked in the rear the Roman soldiers and sailors crowded together on the mole of the transverse wall, and drove the whole mass in wild confusion into the sea. A part were taken on board by the Roman ships; but more were drowned. Some four hundred soldiers and a still greater number of men belonging to the fleet were sacrificed on this day; the general himself, who had shared the fate of his men, had been obliged to seek refuge in his ship, and, when this sank from having been overloaded with men, he had to save himself by swimming to another. But, severe as was the loss suffered, it was amply compensated by the recovery of the lighthouse-island, which along with the mole as far as the first arch-opening remained in the hands of Caesar. At length the longed-for relief arrived, Mithridates of Pergamus, an able warrior of the school of Mithridates Eupator, whose natural son he claimed to be, brought up by land from Syria a motley army,--the Ituraeans of the prince of the Libanus, the Bedouins of Jamblichus, son of Sampsiceramus, the Jews under the minister Antipater, and the contingents generally of the petty chiefs and communities of Cilicia and Syria. From Pelusium, which Mithridates had the fortune to occupy on the day of his arrival, he took the great road towards Memphis, with the view of avoiding the intersected ground of the Delta and crossing the Nile before its division; during which movement his troops received manifold support from the Jewish peasants who were settled in this part of Egypt. The Egyptians, with the young king Ptolemy now at their head, whom Caesar had released to his people in the vain hope of allaying the insurrection by his means, despatched an army to the Nile, to detain Mithridates on its farther bank. The army fell in with the enemy even beyond Memphis at the so-called Jews' camp, between Onion and Heliopolis; nevertheless Mithridates, trained in the Roman fashion of manoeuvring and encamping, amidst successful conflicts gained the opposite bank at Memphis. Caesar, on the other hand, as soon as he obtained news of the arrival of the relieving army, conveyed a part of his troops in ships to the end of the lake of Morea to the west of Alexandria, and marched round this lake and down the Nile to meet Mithridates advancing up the river.