The small degree of domestic peace and comfort which Lysimachus had hitherto enjoyed was far from being improved by this change. The family of Ptolemy was distracted by a deadly feud, and, by means of the marriage of Arsinoe with Lysimachus, and of another marriage which subsequently occurred, and which will be spoken of presently, the quarrel was transferred, in all its bitterness, to the family of Lysimachus, where it produced the most dreadful results.
The origin of the quarrel in the household of Ptolemy was this: Ptolemy married, for his first wife, Eurydice, the daughter of Antipater. When Eurydice, at the time of her marriage, went with her husband into Egypt, she was accompanied by her cousin Berenice, a young and beautiful widow, whom she invited to go with her as her companion and friend. A great change, however, soon took place in the relations which they sustained to each other. From being very affectionate and confidential friends, they became, as often happens in similar cases, on far less conspicuous theatres of action, rivals and enemies. Berenice gained the affections of Ptolemy, and at length he married her. Arsinoe, whom Lysimachus married, was the daughter of Ptolemy and Berenice. They had also a son who was named Ptolemy, and who, at the death of his father, succeeded him on the throne. This son subsequently became renowned in history under the name of Ptolemy Philadelphus. He was the second monarch of the Ptolemaic line.
But, besides these descendants of Berenice, there was another set of children in Ptolemy's family--namely, those by Eurydice. Eurydice had a son and a daughter. The name of the son was Ptolemy Ceraunus; that of the daughter was Lysandra. There was, of course, a standing and bitter feud always raging between these two branches of the royal household. The two wives, though they had once been friends, now, of course, hated each other with perfect hatred. Each had her own circle of partisans and adherents, and the court was distracted for many years with the intrigues, the plots, the dissensions, and the endless schemes and counterschemes which were resorted to by the two parties in their efforts to thwart and circumvent each other. As Arsinoe, the wife of Lysimachus, was the daughter of Berenice, it might have been expected that the influence of Berenice's party would prevail in Lysimachus's court. This would doubtless have been the case, had it not been that unfortunately there was another alliance formed between the two families which complicated the connection, and led, in the end, to the most deplorable results. This other alliance was the marriage of Agathocles, the son of Lysimachus, with Lysandra, Eurydice's daughter. Thus, in the court and family of Lysimachus, Berenice had a representative in the person of her daughter Arsinoe, the wife of the king himself; while Eurydice, also, had one in the person of her daughter Lysandra, the wife of the king's son. Of course, the whole virulence of the quarrel was spread from Egypt to Macedon, and the household of Lysimachus was distracted by the dissensions of Arsinoe and Lysandra, and by the attempts which each made to effect the destruction of the other.