Ptolemy XIII Theos Philopator in the context of "Ptolemy XII"

Cleopatra VII Thea Philopator (Koine Greek: Κλεοπάτρα Θεά Φιλοπάτωρ, lit. 'Cleopatra father-loving goddess'; 70/69 BC – 10 or 12 August 30 BC) was Queen of the Ptolemaic Kingdom of Egypt from 51 to 30 BC, and the last active Hellenistic pharaoh. A member of the Ptolemaic dynasty, she was a descendant of its founder Ptolemy I Soter, a Macedonian Greek general and companion of Alexander the Great. Her first language was Koine Greek, and she is the only Ptolemaic ruler known to have learned the Egyptian language, among several others. After her death, Egypt became a province of the Roman Empire, marking the end of the Hellenistic period in the Mediterranean, which had begun during the reign of Alexander (336–323 BC).

Born in Alexandria, Cleopatra was the daughter of Ptolemy XII Auletes, who named her his heir before his death in 51 BC. Cleopatra began her reign alongside her brother Ptolemy XIII, but a falling-out between them led to a civil war. Roman statesman Pompey fled to Egypt after losing the 48 BC Battle of Pharsalus against his rival Julius Caesar, the Roman dictator, in Caesar's civil war. Pompey had been a political ally of Ptolemy XII, but Ptolemy XIII had him ambushed and killed before Caesar arrived and occupied Alexandria. Caesar then attempted to reconcile the rival Ptolemaic siblings, but Ptolemy XIII's forces besieged Cleopatra and Caesar at the palace. Shortly after the siege was lifted by reinforcements, Ptolemy XIII died in the Battle of the Nile. Caesar declared Cleopatra and her brother Ptolemy XIV joint rulers, and maintained a private affair with Cleopatra which produced a son, Caesarion. Cleopatra traveled to Rome as a client queen in 46 and 44 BC, where she stayed at Caesar's villa. After Caesar's assassination, followed shortly afterwards by the sudden death of Ptolemy XIV (possibly murdered on Cleopatra's order), she named Caesarion co-ruler as Ptolemy XV.

The siege of Alexandria was a series of skirmishes and battles occurring between the forces of Julius Caesar, Cleopatra VII, Arsinoe IV, and Ptolemy XIII, between 48 and 47 BC. During this time Caesar was engaged in a civil war against remaining Republican forces.

The siege was lifted by relief forces arriving from Syria. After a battle contesting those forces' crossing of the Nile delta, Ptolemy XIII and Arsinoe's forces were defeated.

Pothinus or Potheinos (Ancient Greek: Ποθεινός; early 1st century BC – 48 or 47 BC), a eunuch, was regent for Pharaoh Ptolemy XIII Theos Philopator of the Ptolemaic Kingdom. He is most remembered for turning Ptolemy against his sister and co-ruler Cleopatra, thus starting a civil war, and for having Pompey decapitated and presenting the severed head to Julius Caesar according to some sources.

When Ptolemy XII died in 51 BC, his will stated that Ptolemy XIII and Cleopatra VII were to become co-rulers of Egypt, with the Roman Republic as their guardians. Ptolemy XIII was underage and Pothinus was appointed as his regent. The general Achillas and the rhetorician Theodotus of Chios were also guardians of the Egyptian king. When Ptolemy and Cleopatra were elevated to the status of senior rulers, Pothinus was maintained as the former's regent. Most Egyptologists believed that Pothinus used his influence to turn Ptolemy against Cleopatra. In the spring of 48 BC, Ptolemy, under Pothinus' guidance, attempted to depose Cleopatra in order to become sole ruler while Pothinus planned to act as the power behind the throne. They gained control of Alexandria, then the capital of Egypt, and forced Cleopatra out of the city. She soon organized her own army and a civil war began in Egypt, while Arsinoe IV also began to claim the throne for herself.

Arsinoë IV (Ancient Greek: Ἀρσινόη; between 68 and 63 BC – 41 BC) was the youngest daughter of Ptolemy XII Auletes. One of the last members of the Ptolemaic dynasty, she claimed title of Queen of Ptolemaic Egypt and co-rulership with her brother Ptolemy XIII in 48 BC – 47 BC in opposition to her sister or half-sister, Cleopatra VII. For her role in conducting the siege of Alexandria (47 BC) against Cleopatra, Arsinoë was taken as a prisoner of war to Rome by the Roman triumvir Julius Caesar following the defeat of Ptolemy XIII in the Battle of the Nile. Arsinoë was then exiled to the Temple of Artemis at Ephesus in Roman Anatolia, but she was executed there by orders of triumvir Mark Antony in 41 BC at the behest of his lover Cleopatra VII.

Achillas (Greek: Ἀχιλλᾶς; died 47 BC) was one of the guardians of the Egyptian king Ptolemy XIII Theos Philopator, and commander of the king's troops, when Pompey fled to Egypt in September 48 BC. He was called by Julius Caesar a man of extraordinary daring, and it was he and Lucius Septimius who killed Pompey at the suggestion of the eunuch Pothinus and Theodotus of Chios.

Achillas subsequently joined Pothinus in resisting Caesar, and having had the command of the whole army entrusted to him by Pothinus, he marched against Alexandria with 20,000 infantry and 2,000 cavalry. Caesar, who was at Alexandria, did not have sufficient forces to oppose him, and sent ambassadors to negotiate with him. However, Achillas murdered the ambassadors to remove all hopes of reconciliation. He then marched into Alexandria and some of the city. Meanwhile, Arsinoe, the younger sister of Ptolemy, escaped from Caesar and joined Achillas. However, in 47 BC, dissension broke out between them, so Arsinoe had Achillas put to death by Ganymedes, a eunuch to whom she then entrusted the command of the forces.