Arsinoe III of Egypt in Wikipedia
Arsinoe III (Greek: Ἀρσινόη ἡ Φιλοπάτωρ, which means "Arsinoe the father-loving", 246 or 245 BC - 204 BC) was Queen of Egypt (220 - 204 BC). She was a daughter of Ptolemy III and Berenice II.
Between late October and early November 220 BC she was married to her brother, Ptolemy IV. She took active part in the government of the country, at least in the measure that it was tolerated by the all-powerful minister Sosibius. She rode at the head of infantry and cavalry to fight Antiochus the Great at the battle of Raphia in 217 BC. She was the mother of Ptolemy V. In summer, 204 BC she was murdered in a palace coup, shortly after her husband's own death.