Alexandrian War (48-47 BC): Caesar, Cleopatra and Ptolemy XIII

The Alexandrian War was a conflict fought in Alexandria and the Nile Delta from October 48 BC to early 47 BC between Julius Caesar and the forces of the young Egyptian king Ptolemy XIII. Caught with a small force in a hostile city, Caesar held the royal quarter for months until a relief army arrived and he won a decisive battle near the Nile. The war confirmed Cleopatra VII as ruler of Egypt and began her partnership with Caesar.

Background: two wars collide

Egypt in 48 BC was divided by a dynastic quarrel. Ptolemy XII Auletes had died in 51 BC, leaving the throne jointly to his daughter Cleopatra VII and his son Ptolemy XIII. By 48 BC the boy king’s advisers, the eunuch Pothinus, the general Achillas and the rhetorician Theodotus of Chios, had driven Cleopatra out, and she was gathering forces on the border near Pelusium.

At the same time, Rome was in civil war. Caesar defeated Pompey the Great at the Battle of Pharsalus in Greece in August 48 BC. Pompey fled by sea to Egypt, hoping for help from Ptolemy XIII, whose father he had supported. On 28 September 48 BC, as he came ashore near Pelusium, he was stabbed to death on the orders of Ptolemy’s advisers, who hoped to win Caesar’s favour.

Caesar arrives in Alexandria

Caesar reached Alexandria a few days later with a small force, about 3,200 legionaries and 800 cavalry by his own account. He was shown Pompey’s head and, according to ancient writers, wept and turned away. Instead of leaving, he landed, entered the city with the official signs of a Roman consul and installed himself in the royal palace.

This display angered the Alexandrians, who saw it as an insult to their king. Caesar announced that he would settle the dispute between Ptolemy XIII and Cleopatra according to their father’s will, which had placed them under Roman protection. He also demanded repayment of large debts Ptolemy XII owed to Roman creditors, including Caesar himself.

Cleopatra, unable to pass Ptolemy’s troops, had herself brought secretly into the palace by her follower Apollodorus the Sicilian, hidden, according to Plutarch, in a bedding bag. She won Caesar’s support. When Ptolemy XIII saw that Caesar favoured his sister, he rushed into the streets declaring he had been betrayed and stirred up the crowd.

The siege of the palace quarter

Pothinus summoned Achillas, who marched on Alexandria with about 20,000 infantry and 2,000 cavalry, among them former Roman soldiers left in Egypt by Aulus Gabinius in 55 BC. Caesar, keeping the young king under his control, fortified part of the royal quarter near the harbour.

The fighting was fierce and confused. To prevent the Egyptians from using the fleet in the harbour against him, Caesar burned the ships at anchor. The fire spread to buildings near the docks, and later writers said that many books were destroyed. Whether these were scrolls stored in warehouses or part of the Library of Alexandria is debated, but the Library itself survived.

Caesar then seized the island of Pharos, with its famous lighthouse, to keep control of the harbour entrance and his link with the sea. Pothinus, discovered sending messages to Achillas, was executed.

Arsinoe, Ganymedes and the water supply

Cleopatra’s younger sister Arsinoe IV escaped from the palace with her tutor, the eunuch Ganymedes, and joined the Egyptian army, where she was proclaimed queen. After a quarrel she had Achillas killed, and Ganymedes took command.

Ganymedes tried to force Caesar out by contaminating the water supply. Alexandria relied on underground channels fed from the Nile, and he pumped seawater into the channels serving Caesar’s quarter. Caesar’s soldiers dug new wells and, after a night’s work, found fresh water.

Several naval battles followed in and around the harbours. In an attack on the Heptastadion, the causeway linking Pharos to the mainland, Caesar’s troops were driven back in panic. Caesar had to abandon his ship and swim to safety; Suetonius and Plutarch say he held papers above the water as he swam. Hundreds of his soldiers and sailors were lost.

The Alexandrians then asked Caesar to release Ptolemy XIII, claiming they wanted peace. Caesar let him go, perhaps expecting little from it. The young king immediately took command of the army against him.

The Battle of the Nile

Relief came from the east. Mithridates of Pergamum, an ally of Caesar, led an army through Syria, joined by a force of Jewish soldiers under Antipater, the Idumaean father of Herod the Great. They stormed Pelusium and marched up the eastern side of the Delta.

Ptolemy XIII moved to stop them, and Caesar sailed out to join Mithridates. The decisive battle was fought in early 47 BC near a branch of the Nile in the Delta; the exact site is uncertain, but it probably lay north of modern Cairo. Caesar’s veterans stormed the Egyptian camp. Ptolemy XIII fled, and the boat carrying him and other fugitives capsized; he drowned in the river.

Caesar rode back to Alexandria, which surrendered without further fighting.

Aftermath

Caesar confirmed Cleopatra as queen, with her remaining brother Ptolemy XIV, aged about 12, as her husband and co-ruler. Arsinoe IV was sent to Rome, where she was led in Caesar’s triumph in 46 BC and then allowed to live in exile at Ephesus. Three legions were left in Egypt to support Cleopatra’s rule.

According to Suetonius, Caesar then took a long journey up the Nile with Cleopatra, although some historians doubt the details. By mid-47 BC he left Egypt to deal with Pharnaces II of Pontus, whom he crushed at the Battle of Zela in August. Cleopatra’s son Caesarion was born in 47 BC.

The war had lasting consequences. It tied Egypt’s last great ruler to the Roman leadership and made Egypt a Roman client kingdom in all but name. It also delayed Caesar’s final campaigns against the remaining Pompeians in Africa and Spain, giving them time to regroup.

The sources

Unusually for an ancient war, the Alexandrian War is described by participants. Caesar’s own Civil War breaks off at the beginning of the siege. The story is continued in the Alexandrian War (Bellum Alexandrinum), written by one of Caesar’s officers, traditionally identified as Aulus Hirtius, who was not present in Alexandria himself but had access to those who were.

Both works naturally favour Caesar and say little about Cleopatra. Later writers, especially Plutarch, Suetonius and Cassius Dio, add personal details such as the bedding bag, the swim in the harbour and the burning of books, but they wrote a century or more afterwards. Historians use all these accounts together, while noting that the exact chronology of the siege remains uncertain.

Timeline

• 51 BC: Ptolemy XII dies; Cleopatra VII and Ptolemy XIII become joint rulers.
• 9 August 48 BC: Caesar defeats Pompey at Pharsalus (date in the pre-Julian calendar).
• 28 September 48 BC: Pompey is murdered on landing near Pelusium.
• Early October 48 BC: Caesar arrives in Alexandria.
• Late 48 BC: Achillas besieges Caesar; ships in the harbour are burned.
• Winter 48–47 BC: Fighting for the harbours; Caesar swims to safety at the Heptastadion.
• Early 47 BC: Mithridates of Pergamum takes Pelusium; Caesar wins the Battle of the Nile and Ptolemy XIII drowns.
• Mid-47 BC: Caesar leaves Egypt for Asia Minor.

Why it matters

The Alexandrian War nearly cost Caesar his life at the height of his power, yet it ended with Rome’s most powerful man and Egypt’s queen in alliance. That alliance shaped the last chapter of Ptolemaic Egypt and, through Cleopatra VII, the Roman civil wars that followed.