|Siege of Alexandria|
|Part of Alexandrine Civil War|
|Roman Republic||Ptolemaic Kingdom|
|Commanders and leaders|
Gaius Julius Caesar|
Arsinoe IV (POW)
Elements of Legio VI and Legio XXVII
An unknown number of militia
|Casualties and losses|
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 the forces of the Roman Senate.
After the Battle of Pharsalus, between the forces of Caesar and those of Gnaeus Pompey Magnus and the Senate, the majority of the forces commanded by Pompey were scattered or surrendered to Caesar. Pompey, however, escaped via Amphipolis to Egypt, only to be killed upon landing in Egypt by Achillas and Lucius Septimius, former soldiers in his army. The assassination was proposed by the eunuch Pothinus and Theodotus of Chios, advisors of the pharaoh Ptolemy who deemed that Caesar would be pleased by the removal of his adversary.
Caesar was either horrified, or pretended to be horrified, at the murder of Pompey, and wept for his one-time ally and son-in-law. In an effort to mitigate the damage done to Rome's government and to Caesar's reputation, he planned to pardon all former Pompeians who surrendered to his forces, and the crown jewel of that would have been to pardon Pompey, which was now impossible. He demanded the money Ptolemy's father Ptolemy XII Auletes had been lent by Rome and agreed to settle the dispute between Ptolemy and his sister and co-regent Cleopatra VII. Caesar chose to favor Cleopatra over her brother.
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 on foot 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 occupied most of the city. Meanwhile, Arsinoe IV, the younger sister of Ptolemy, escaped from Caesar and joined Achillas. In 47 BC, dissension broke out between them, and Arsinoe had Achillas put to death by Ganymedes, a eunuch to whom she then entrusted the command of the forces. Ganymedes initially enjoyed some success against Caesar, who had only the soldiers he had brought with him and a minor Italian militia left over from previous issues in 55 BC. However, soon after the hostilities broke out, Caesar was reinforced by the 36th legion from Asia Minor.
Soon after the siege began Caesar made a sally against the Great Harbor and burned the Alexandrian fleet, damaging the Great Library in the process. Ganymedes ordered the Alexandrians to make repairs on as many ships as possible. They were able to ready 27 warships for battle. Caesar unwilling to give up his naval superiority drew up his own fleet, 19 warships and 15 smaller vessels, in two lines just north of the coast of Pharos Island. Ganymedes sailed out from the Eunostos Harbor and formed two lines opposite Caesar's fleet. Between the two fleets were shoals, a narrow channel being the only way through. Both sides eventually held their position neither wanting to make the initial move. Euphranor, the commander of Caesar's Rhodian allies, convinced Caesar he and his men could push through and hold for long enough to let the rest of the fleet pass through the channel. Four Rhodian ships sailed through the channel and formed a line against the Alexandrian ships rapidly closing in delaying them long enough for the rest of Caesar's fleet to pass through. With the channel to his back Caesar needed to win because retreat would be disastrous. Though the Alexandrians were excellent sailors the Romans had one deciding advantage: because of the proximity of the coast and the shoals there was little room for manoeuvre. The ships were forced into close combat something the Romans excelled at. Two Alexandrian ships were captured, three more were sunk, the rest fled back to the Eunostos.
The Battle for Pharos Island
After winning the battle for naval supremacy Caesar turned his attention to Pharos Island. The island was crucial for controling access into the harbors and was linked to the mainland through a bridge, the Heptastadium, connected by two moles, one from the island one from the mainland. Caesar had stationed a small garrison on the north-Eastern part of the island opposite the Lighthouse of Alexandria. He ordered ten cohorts of legionaries, some light infantry and his Gallic cavalry to board their transports and led them on an amphibious assault of the island while his garrison on the island attacked the Alexandrians simultaneouly. After a hard fought battle the Alexandrians retreated from the island. Caesar fortified defences around the bridge controling access to the Pharos, the Alexandrians doing the same on the mainland. The bridge had a large arch through which the Alexandrians could send ships to attack Caesar's transports. In order to stop the Alexandrians from doing this Caesar needed to take controle of the bridge. The day after taking the island he sent several ships with archers and artillery to clear the bridge and then landed himself with three cohorts on the bridge. He ordered his men to start constructing a rampart on the bridge while men from the Pharos brought up stones to block the arch. The Alexandrians suddenly launched an two-pronged counterattack by land and sea in order to take the bridge back. Caesar's captains decided to take the initiative themselves by landing archers and slingers on the bridge to fend off the enemy ships. The Alexandrians however landed their troops behind them and attacked them from the rear. Caesar's light troops were quickly outfought by the heavily armed Alexandrian soldiers. Caesar was now caught in a pincer and ordered his troops to withdraw to their transports. Due to the panic which ensued some transports took on too many troops and started to capsize. So did Caesar's. He stripped his armour, dove into the water and swam to the next transport. The battle ended in defeat; although Pharos Island was still in Caesar's hands the bridge was not. He had lost 400 legionaries and another 400 sailors and light infantry.
The leading Egyptian officers were soon dissatisfied with the eunuch. Under a pretext of wanting peace, they negotiated with Caesar to exchange Arsinoë for Ptolemy XIII, who was subsequently released only to continue the war.
About a month later Caesar's fortunes started to turn. He got word that his reinforcements, the 35th legion and his allies from Asia Minor, were marching through Syria and the Levant and would be arriving soon. Supplies from Asia Minor were being sent by ship. The Alexandrians got word of this and tried to intercept the supply convoy. Caesar sent his own ships commanded by Tiberius Nero and Euphranor to protect his allies' supply ships. Though the Romans were able to win the battle, Euphranor's ship was surrounded and he was killed.
Relief for the Romans came from Mithridates of Pergamum and Antipater from Judea who led a 13,000 strong relief army into Egypt. A final pitched battle was fought on the west side of the Nile River with Caesar victorious and Ptolemy drowning while attempting to cross the river.
Ptolemy's crown was passed to his younger brother Ptolemy XIV and Cleopatra as co-rulers. Caesar reportedly toured Egypt for two months with Cleopatra before renewing his activities in the civil war. Arsinoe was marched through Rome as a prisoner, banished to the Temple of Artemis in Ephesus, and later, (after the death of Caesar,) executed on the orders of Cleopatra and Mark Antony.
- Julius Caesar, Commentarii de Bello Civili iii. 104
- Livy, Epit. 104
- Cassius Dio xlii. 4
- Smith, William (1867), "Achillas", in Smith, William (ed.), Dictionary of Greek and Roman Biography and Mythology, 1, Boston, MA, p. 9
- Julius Caesar, Commentarii de Bello Civili iii. 108—112
- B. Alex. 4
- Cassius Dio xlii. 36—40
- Lucan x. 519— 523
- De Bello Alexandrino 23-24 and, with some deviations, Cassius Dio, Roman History 42.42
- M. Cary and H. H. Scullard, A History of Rome