Crossing the Egyptian border In December 639,
Amr ibn al-As left for Egypt with a force of 4,000 troops. The invading army included units from various Arab tribes, especially from
Yemen. Most of the soldiers belonged to the Arab tribe of 'Ak, but
Al-Kindi mentioned that one third of the soldiers belonged to the Arab tribe of Ghafik. The Arab army also contained many
apostates whom the
Caliph Abu Bakr forced back into Islam during the
Ridda Wars.
Amr ibn al-As enticed these various groups by promising them war booty, spoils and captives in return for their help in battles leading to the invasion. In total, the invaders numbered between twelve and fifteen thousand men. However,
Umar, the Muslim
caliph, reconsidered his orders to Amr and considered it unwise to expect to conquer such a large country as Egypt with a mere 4,000 soldiers. Accordingly, he wrote a letter to Amr ordering him to "return with all haste to the court of the Caliph, so that his soldiers might join additional campaigns being planned elsewhere". However, there was a provision in the letter stating that Amr's first duty was the protection of his troops, and if he found himself on Egyptian soil by the time he received the letter, the Caliph would leave overall strategic command of movement to him, so as to not unduly burden troops already in the field. The messenger,
Uqba ibn Amir, caught up with Amr at
Rafah, a little short of the Egyptian frontier. Guessing what might be in the letter, Amr ordered the army to quicken its pace. Turning to Uqbah, Amr said that he would receive the caliph's letter from him when the army had halted after the day's journey. Uqbah, unaware of the contents of the letter, agreed and marched along with the army. The army halted for the night at Shajratein, a little valley near the city of
El Arish, which Amr knew to be beyond the Egyptian border. Amr then received and read Umar's letter and went on to consult his companions as to the course of action to be adopted. The unanimous view was that as they had received the letter on Egyptian soil, they had permission to proceed. When Umar received the reply, he decided to watch further developments and to start concentrating fresh forces at Madinah that could be dispatched to Egypt as reinforcements. On
Eid al-Adha, the Muslim army marched from Shajratein to
El Arish, However,
Alfred J. Butler dismisses Armenousa's story as a myth. The losses incurred by the Muslim army were ameliorated by the number of Sinai
Bedouins, who, taking the initiative, had joined them in conquering Egypt. The Bedouins belonged to the tribes of Rashidah and Lakhm. The ease with which
Pelusium fell to the Muslims and the lack of Roman reinforcements during the month-long siege is often attributed to the treachery of Cyrus, who was also the
Greek Patriarch of Alexandria (not the one recognised by most of the population, who was
Pope Benjamin I). After the fall of Pelusium, the Muslims marched to
Belbeis, 65 km (40 mi) from
Memphis via desert roads, and besieged it.
Belbeis was the first place in Egypt that the Byzantines showed some measure of resistance towards the Arabs. Two Christian monks, accompanied by Cyrus of Alexandria and the famous Roman general
Aretion, came out to negotiate with 'Amr ibn al-'As. Aretion had been the Byzantine governor of
Jerusalem, but had gone to Egypt shortly after losing the
Battle of Ajnadayn. 'Amr gave them three options: convert to Islam, pay the
jizya, or fight. They requested three days to reflect and then, according to
Al-Tabari, requested two extra days. At the end of the five days, the two monks and the general decided to reject Islam and the jizya and fight the Muslims, thus disobeying Cyrus, who wanted to surrender and pay jizya. Cyrus left for the
Babylon Fortress. The battle resulted in a Muslim victory during which Aretion was killed and Armenousa was captured, but sent back to Cyrus. 'Amr ibn al-'As subsequently attempted to convince the native Egyptians to aid the Arabs and surrender the city, based on the kinship between Egyptians and Arabs via
Hajar. When the Egyptians refused, the siege resumed until the city fell around the end of March 640. Babylon was a fortified city, and
Theodore had indeed prepared it for a siege. Outside the city, a
ditch had been dug, and a large force was positioned in the area between the ditch and the city walls. The Muslims besieged the fort, a massive structure high with walls more than thick and studded with numerous
towers and
bastions and a force of some 4,000 men. Early Muslim sources place the strength of the Byzantine force in Babylon at about six times the strength of the Muslim force. For the next two months, fighting remained inconclusive, with the Byzantines repulsing every Muslim assault. The Arabs then noticed that John, with a small group of 50 men, had been following them. John and his men retreated to their base at
Abûît, but their hiding place was betrayed by a
Bedouin chief and they were all killed. When news of John's death reached
Theodore, who was commanding the garrison at
Babylon, 'his lamentations were more grievous than
the lamentations of David over Saul when he said: "How are the mighty fallen, and the weapons of war perished!"' as
John of Nikiu puts it.
Battle of Heliopolis When Zubayr arrived, he pointed out to 'Amr that the Roman-garrisoned city of
Heliopolis was a short distance away, and that troops from there could relieve the Siege of Babylon. To remove this threat, 'Amr went with about half of his men there. The city boasted the Sun Temple of the
Pharaohs and grandiose monuments and learning institutions. There was the danger that forces from Heliopolis could attack the Muslims from the flank while they were engaged with the Roman army at Babylon. There was a cavalry clash near the current neighbourhood of
Abbaseya. The engagement was not decisive, but it resulted in the occupation of the fortress located between the current neighborhoods of Abdyn and
Azbakeya. The defeated Byzantine soldiers retreated to either the Babylon Fortress or the fortress of Nikiû. Zubayr and some of his handpicked soldiers scaled the Heliopolis city wall at an unguarded point and, after overpowering the guards, opened the gates for the army to enter the city. After the capture of Heliopolis, 'Amr returned to Babylon.
Conquering of Fayoum and Babylon in
Old Cairo When news of the Muslims' victory at
Heliopolis reached Fayoum, its governor, Domentianus, and his troops fled without informing the people of Fayoum and Abuit that they were abandoning their cities to the enemy. When news reached 'Amr, he sent troops across the
Nile to invade Fayoum and Abuit, capturing the entire province of Fayoum with practically no resistance. Fayoum's population
was enslaved, and the city was looted (the traditional fate of cities that had resisted). Emissaries were exchanged between Theodore and 'Amr, leading to 'Amr meeting Theodore in person. Then, with negotiations stalled, during the night of 20 December, a company of handpicked warriors, led by Zubayr, managed to scale the wall, kill the guards, and open the gates for the Muslim army to enter. The city was captured by the Muslims the following morning with tactics similar to those that had been used by Khalid ibn Walid at Damascus. However, Theodore and his army managed to slip away to the island of Rauda during the night, whence they continued to fight the Muslims. During this time, Theodore assembled an army in the
Nile Delta and put two generals in charge of defending
Samannud. Hearing of this, 'Amr went north to destroy this army. The two generals in Samannud refused to fight the Muslims, but Theodore fought 'Amr there and defeated him, inflicting many casualties on the Muslims. Unable to damage any cities in the
Nile Delta, they retreated back to Babylon. However, Theodore was unable to follow up this victory by recapturing Babylon. recognizing Muslim sovereignty over the whole of Egypt and effectively over
Thebaid, and agreeing to pay Jizya at the rate of 2 diners per male adult. Cyrus asked Heraclius to ratify the treaty and offered an argument in support. 'Amr submitted a detailed report to Umar recommending ratification. Upon hearing about this, Heraclius was furious and had Cyrus recalled to
Constantinople. Cyrus tried to defend his actions, but Heraclius angrily threatened to kill him, calling him an abject coward and a heathen, and asking whether 100,000 Romans were a match for 12,000 barbarians. He then handed him to the city Prefect to humiliate him, and sent him to exile.
March to Alexandria in Alexandria (present-day archeological site of
Kom El Deka) The Byzantine commanders, knowing full well that the Muslims' next target was Alexandria, set out to repel the Muslims through continued sallies from the fort or, at least, to exhaust them and erode their morale in a campaign of attrition. However, the captain of the ship claimed the wind was contrary to him, and Theodore was stuck with Cyrus. They returned to
Alexandria on September 14, 641, the
Feast of the Cross. was carried with Cyrus and Theodore. The procession passed between
Cleopatra's Needles and entered the
Caesareum Church, where a
liturgy was prayed. The
Psalm reading of the day was , but the deacon said another psalm hoping to praise Cyrus and congratulate him on his return. This was said to be a bad omen. Cyrus then gave a sermon about the
discovery of the True Cross, perhaps encouraging them to resist the siege in the name of the Cross, despite having already decided in himself to forsake the Cross and surrender to the Muslims. ==Invasion of Nubia==