Arsinoe I [SEP] sister
Arsinoe I
Arsinoe I (, 305 BC – after c. 248 BC) was Queen of Egypt by marriage to Ptolemy II Philadelphus. 
Life.
She was the second daughter and youngest child born to King Lysimachus and Nicaea of Macedon. Arsinoe I had two older siblings: a brother called Agathocles and a sister called Eurydice.
Arsinoe's paternal grandfather was Agathocles of Pella, a nobleman who was a contemporary to King Philip II of Macedon who reigned 359-336 BC, while her maternal grandfather was the powerful
's first wife, Arsinoe I (daughter of the late King Lysimachus of Thrace) is accused, probably at instigation of Ptolemy II's sister (who also has the name Arsinoe), of plotting his murder and is exiled by the King. Arsinoe then marries her own brother, a customary practice in Egypt, but scandalous to the Greeks. The suffix "Philadelphoi" ("Brother-Loving") consequently is added to the names of King Ptolemy II and Queen Arsinoe II. The former queen, Arsinoe I,