Cleopatra IV (d. 112 BCE), like her sisters Tryphaena and Cleopatra Selene I, ended up being more heavily involved in Seleukid politics and wars than in affairs in Egypt, where she was born. Though some make her out to be merely the victim of others’ plots, she acted on her own as well, helping on one occasion to turn the tide for her last husband, Antiochos IX Cyzicenus.
Cleopatra was the child of Cleopatra III and Ptolemy VIII, probably the middle of their three daughters who survived to adulthood. She grew up on Cyprus, well away from the civil war between her parents and stepmother/aunt/grandmother, Cleopatra II. She first married the elder of her two brothers, the future Ptolemy IX, and had at least one son sometime before their father died. With Ptolemy VIII’s death, Cleopatra III would have preferred to make her younger son king, but when forced to choose the elder, she made him divorce Cleopatra and marry Cleopatra Selene instead.
Cleopatra herself was still on Cyprus when she found out she had been divorced and deprived of a throne. She assembled an army, mostly persuading the men of the Seleukid king Antiochos VIII Grypus, her sister Tryphaena’s husband, to follow her instead. Rather than march on Egypt though, she took them to Antiochos IX Cyzicenus, Grypus’s younger brother and rival and offered him both the army and her hand in marriage. He agreed and the two were married.
With the army Cleopatra brought him, Cyzicenus finaly had enough men to rebel against his brother, starting a civil war. Tryphaena, however, took her sister and sister-in-law’s actions as a very badly and accused Cleopatra of invading the country out of rivalry and envy and of bringing in a foreign army to deal with a dispute between brothers. When Cleopatra was trapped in Antioch and too refuge in a temple, Tryphaena had her dragged out and killed. Tryphaena herself would not live even a year beyond that. Cyzicenus captured her and had her executed in revenge for his wife’s murder.
Justin, Epitome of the Philippic HIstory 39.3 - Attalus.org
Cleopatra IV - Egyptian Royal Genealogy
Cleopatra IV - Livius.org