Cleopatra was a daughter of king Philip of Macedonia (359-336) and queen Olympias. Her older brother was prince Alexander, who would one day be called "the Great". Philip was a powerful man, who could appoint kings in neighboring states, such as Molossis, where he chose Olympias' brother Alexander in 350. Twelve years later, Philip defeated the Greeks; in 337, he reorganized the conquered territories in the Corinthian league. At the same time, he married to a woman named Cleopatra, the daughter of the brother of an important Macedonian aristocrat named Attalus. As could be expected, this created tensions within the royal family.
Olympias went into voluntary exile, staying at the Molossian court of her brother Alexander. Her son Alexander and his friends (e.g., Ptolemy and Nearchus) were briefly expelled. Only princess Cleopatra stayed with her father and her new stepmother. However, Philip decided to isolate his former wife by marrying Cleopatra to Alexander of Molossis (October 336). In this way, Olympias could no longer count on her brother's support.
The marriage ceremony was a disaster, because the father of the bride was assassinated during the festivities by a man who had a personal grieve. The results were that crown prince Alexander of Macedonia became king, Olympias could return home, and Philip's wife Cleopatra was forced to suicide (her baby was killed). Alexander of Molossis and his new queen Cleopatra left Macedonia and settled in the western kingdom, maintaining friendly relations to Macedonia. The couple had two children, a daughter and a son Neoptolemus.
In 334, Alexander of Macedonia set out to conquer the Achaemenid empire. At the same time, the Molossian Alexander decided to intervene in the west, where the divided Greek colonies in Italy were threatened by the federation of mountain tribes that is known as the Samnites. They were formidable warriors who had, in the preceding century, conquered several Greek towns. At first, Alexander was successful, but was he killed in action in 331. Cleopatra, who had been with her husband, returned to Molossis.
In the meantime, Alexander had reached Egypt. Macedonia was ruled by a trusted officer named Antipater. Unfortunately, he and Olympias were not on speaking terms, and in 330, the queen-mother decided to go to her daughter in Molossis. As it turned out, the two queens were not on speaking terms either, so Cleopatra went to the capital of Macedonia, Pella, where she stayed for some time with her two children as guests of Antipater. The relation between the queen and the commander were strained.
On 11 June 323, Alexander the Great died in Babylon. His half-brother Philip Arridaeus succeeded him, but he was a bastard and was considered mentally unfit to rule. Therefore, a regent was appointed, Perdiccas, but he inherited an empire that was very unquiet. For example, in the west, the Greek towns were preparing a revolt. In the Autumn, the Athenians expelled the Macedonians from their town and marched to Thermopylae, which they fortified. In this way, they and their allies hoped to prevent an invasion of Greece by Antipater. They were extremely successful: the commander of the Macedonian forces in Europe was repelled and forced to hide in the nearby fortress of Lamia.
At the same time, Cleopatra intervened. She sent a letter to Leonnatus, a friend, bodyguard and fellow-soldier of Alexander the Great who had, after his king's death, been made satrap of Hellespontine Phrygia by Perdiccas. Cleopatra must have known the man very well because they had both spent their youth at the palace of king Philip. She now wrote him that if he came to Pella, she would marry him. This was a really important change in the political situation: an energetic man like Leonnatus, who had been very close to Alexander and knew how to command an army, would certainly make an excellent candidate to the Macedonian throne if he married Alexander's closest relative. Cleopatra's letter had created a way to get rid of the mentally unfit Philip Arridaeus.
Leonnatus knew that a victory over the rebellious Greeks would enhance his claim to the throne, and went to Lamia, where he lifted the siege and rescued Antipater. However, he was killed in action.
Cleopatra now went to Sardes in Lydia. Our sources state that Olympias had offered her hand to Perdiccas, but it is equally possible that she had taken the initiative herself. The motive of the proposed marriage was the same as the earlier attempt to marry: a union between the sister of Alexander the Great and a general would serve the unity and stability of the empire, because the unstable Philip Arridaeus would be replaced by a stronger man.
There was one complication. Perdiccas was engaged to Antipater's daughter Nicaea, and when the engagement was broken off, Antipater felt insulted. More importantly: several generals wanted at all costs to prevent that Perdiccas became king. Civil war - the First Diadoch War - broke out in the last months of 322: Perdiccas was attacked by the satrap of Egypt Ptolemy, by the generals Craterus and Antigonus Monophthalmus, and by Antipater, who was still the supreme commander of the forces in Europe. A year and a half later, Perdiccas was dead.
Antipater succeeded Perdiccas as regent (320). Cleopatra, who had offended the new "strong man", was forced to side with Eumenes, who had once fought with Perdiccas and now continued a guerilla struggle. But Cleopatra soon discovered that this alliance was fruitless, and she reconciled herself with Antipater. After his death in 319, she stayed in Sardes, and remained unmarried. Generals would sooner start a war than accept that Cleopatra found a husband.
After the death of Antipater, Antigonus Monophthalmus was the most powerful general. He ordered that Cleopatra was to stay under house arrest. In this way, she spent ten years in Sardes. During this period, her son Neoptolemus became king of Molossis (317) and was dethroned (313). After this, the young man may have resided with his mother.
In 308, Ptolemy of Egypt visited the area of the Aegean Sea. Cleopatra knew him well: he too had grown up in the palace of Philip. She tried to escape from Sardes and join the friend of her youth. However, she was caught, brought back to Sardes, and murdered. Although Antigonus executed the assassins and gave Cleopatra a beautiful funeral, the conclusion is inescapable that he had ordered the murder. She represented too much power to remain alive.