This Ptolemy being enamoured of Arsinoe, his sister on both sides, married her, doing what was by no means usual among the Macedonians, but not uncommon among his Egyptian subjects. And next he slew his brother Argæus plotting against him, as was said. And he brought the corpse of Alexander from Memphis. And he slew also another brother, the son of Eurydice, observing that he was trying to make the Cyprians revolt. And Magas the uterine brother of Ptolemy, (being the son of Berenice and one Philip, a Macedonian but one of the common people and otherwise unknown), who had been chosen by his mother to be governor of Cyrene, at this time persuaded the people of Cyrene to revolt from Ptolemy and marched with an army for Egypt. And Ptolemy, having guarded the approaches, awaited the arrival of the men of Cyrene; but Magas having had news brought him on the road that the Marmaridæ had revolted from him, (now the Marmaridæ are a tribe of Libyan Nomads), endeavoured to get back to Cyrene at once. And Ptolemy, intending to follow him, was prevented by the following reason. Among some of his defensive operations against Magas, he had invited in some foreign mercenaries, and among others some 4,000 Galati; but finding that they were plotting to make themselves masters of Egypt, he sent them down to the Nile to a desert island. And here they perished, partly by one another’s sword, partly by famine. And Magas being the husband of Apame, the daughter of Antiochus the son of Seleucus, persuaded Antiochus to violate the conditions which his father Seleucus had made with Ptolemy, and to lead an army into Egypt. But as he was preparing to do so, Ptolemy sent into all parts of Antichus’ dominions guerilla troops to ravage the country where the defenders were weak, and more formidable bodies he checked with his army, so that Antiochus had no longer the chance to invade Egypt. I have previously described how this Ptolemy sent a fleet to aid the Athenians against Antigonus and the Macedonians; but, indeed, the Athenians derived no great benefit from it. Now his sons were not by Arsinoe his sister, but by the daughter of Lysimachus, for although he was married to his sister and lived with her, she pre-deceased him and was childless, and the district Arsinoites is named after her. CHAPTER VIII.