The fourth daughter of Ptolemy XII Auletes, she ruled a portion of his empire, including Phoenicia, Macedonia, and the island Cyprus. Her brother, Egypt and Alexandria jointly with Cleopatra VII. Ptolemy XIII and his officer Pothenius tried to dethrone Cleopatra VII, thus leaving Ptolemy XIII as sole ruler. His relations with Arsinoe deteriorated as well.
During the defeat of the Roman empire, Arsinoe married Ptolemy and joined sides with him, thus joining their two empires into one. As a result, both empires were ruled by Ptolemy XIII at this time. They ended up sending Cleopatra VII back to Alexandria, and they were allies again. When Julius Caesar kidnapped Arsinoe, Ptolemy XIV and Cleopatra VII rescued her and asked for her aid. In 44 BCE after his death, Arsinoe and her army strolled down the streets of Rome in triumph.
After the death of her brother and husband, she was captured by Marc Antony in 42 BCE and sent to Rome. A year later, he poisoned her on orders from Cleopatra VII. Even though she was missed by her sister, Cleopatra VII did this to gain control over Arsinoe's kingdom in 37 BCE.
Arsinoe II (316-270 BC), queen of Thrace and later co-ruler of Egypt with her brother and husband Ptolemy II of Egypt.
Arsinoe II was first married to King Lysimachus of Thrace, to whom she bore three sons.
Arsinoe II shared all of her brother's titles and apparently was quite influential, having towns dedicated to her, her own cult (as was Egyptian custom), and appearing on coinage.