Passage 1.11.5
Ἠπειρῶται δὲ Ἀλκέταν ἐπὶ βασιλείᾳ κατεδέξαντο, Ἀρύββου μὲν παῖδα καὶ ἀδελφὸν Αἰακίδου πρεσβύτερον, ἀκρατῆ δὲ ἄλλως θυμοῦ καὶ διʼ αὐτὸ ἐξελασθέντα ὑπὸ τοῦ πατρός. καὶ τότε ἥκων ἐξεμαίνετο εὐθὺς ἐς τοὺς Ἠπειρώτας, ἐς ὃ νύκτωρ αὐτόν τε καὶ τοὺς παῖδας ἐπαναστάντες ἔκτειναν. ἀποκτείναντες δὲ τοῦτον Πύρρον τὸν Αἰακίδου κατάγουσιν· ἥκοντι δὲ εὐθὺς ἐπεστράτευε Κάσσανδρος, νέῳ τε ἡλικίᾳ ὄντι καὶ τὴν ἀρχὴν οὐ κατεσκευασμένῳ βεβαίως. Πύρρος δὲ ἐπιόντων Μακεδόνων ἐς Αἴγυπτον παρὰ Πτολεμαῖον ἀναβαίνει τὸν Λάγου· καί οἱ Πτολεμαῖος γυναῖκά τʼ ἔδωκεν ἀδελφὴν ὁμομητρίαν τῶν αὑτοῦ παίδων καὶ στόλῳ κατήγαγεν Αἰγυπτίων.
The Epeirots accepted Alcetas as their king, who was the son of Arybbas and older brother of Aeacides, but otherwise uncontrollable in his temper, a trait for which he had been banished by his father. On arriving, he immediately became violent against the Epeirots, until at length they rose up at night against him and killed both him and his children. After his death, they recalled Pyrrhus, the son of Aeacides. Immediately after Pyrrhus had returned, Cassander launched an expedition against him, for Pyrrhus was still young and had not yet secured his rule firmly. Faced with the advancing Macedonians, Pyrrhus fled to Egypt, to Ptolemy son of Lagus. Ptolemy gave him in marriage his own step-sister, who was the maternal sister of his children, and restored him to his kingdom with an Egyptian fleet.