Arsinoe IV

Arsinoë IV
Queen of Egypt
Rescue of Arsinoe, by Jacopo Tintoretto, 1555-1556
Reign	September 48 BC with Ptolemy XIII (December 48  – January 47 BC)
Successor	Ptolemy XIV of Egypt and Cleopatra VII
Born	betw. 68  – 62 BC Alexandria, Egypt
Died	41 BC Ephesus
Burial	Ephesus
House	Ptolemaic dynasty
Father	Ptolemy XII Auletes
Mother	Unknown

Arsinoë IV (Greek: Ἀρσινόη, betw. 68 and 62 BC – 41 BC) was the fourth of six children and the youngest daughter of Ptolemy XII Auletes, and queen and co-ruler of Egypt with Ptolemy XIII from 48 BC – 47 BC, making her one of the last members of the Ptolemaic dynasty of ancient Egypt. Arsinoë IV was the half-sister of Cleopatra VII and also a sibling of Ptolemy XIII.

When Ptolemy XII died in 51 BC, he left his eldest son and daughter, Ptolemy and Cleopatra, as joint rulers of Egypt, but Ptolemy soon dethroned Cleopatra and forced her to flee from Alexandria. Julius Caesar arrived in Alexandria in 48 BC pursuing his rival, Pompey, whom he had defeated at the Battle of Pharsalus. When he arrived in Alexandria, he was presented with Pompey's head. The execution of his longtime friend and foe ended the possibility of an alliance between Caesar and Ptolemy, and instead he sided with Cleopatra's faction. He declared that in accordance with Ptolemy XII's will, Cleopatra and Ptolemy would rule Egypt jointly, and in a similar motion restored Cyprus, which had been annexed by Rome in 58 BC, to Egypt's rule and gifted it to Arsinoë and her youngest brother, Ptolemy XIV. Caesar had Ptolemy's regent, the eunuch Pothinus, executed while the general Achillas escaped and began besieging Alexandria. Arsinoë escaped from the capital with her mentor, the eunuch Ganymedes, and joined the Egyptian army. Achillas then assumed the title of pharaoh.

When Achillas and Ganymedes clashed, Arsinoë had Achillas executed and Ganymedes placed in command of the army and had herself proclaimed queen. Under Ganymedes' leadership, the Egyptians enjoyed some success against the Romans. They drew water from the sea and poured it into the canals that supplied Caesar’s cisterns, which caused a panic among Caesar’s troops. Caesar countered this measure by digging wells into the porous limestone beneath the city that contained fresh water, outwitting the Egyptians. But the leading Egyptian officers were soon dissatisfied with Ganymedes, and under a pretext of wanting peace, they negotiated with Caesar to exchange Arsinoë for Ptolemy XIII, who was subsequently released. However, Ptolemy continued the war until the Romans received reinforcements and inflicted a decisive defeat upon the Egyptians.