Conquest of Chaldea and Hira
As we read before, the Persian (Sassanid) empire was crumbling due to their greedy lords. The taxes were high, and dams and canals were in ruinous position. Chaldea was also called Lower Iraq. The main seat of Persian empire was in Upper Iraq and the regions that were between Arabia and Lower Iraq acted as a vasal state for the empire. The lower Iraq was usually looted and raided by the Arabian tribes residing near the border. A little before the rise of Islam, Bedouin raids had increased intensely, which culminated into the full battle known as Dhu-Qar in 610-11 A.D. The tribe Banu Shayban of Bakr tribe won against the Persians. The Sassanid empire had also been defeated heavily by Hercules of Byzantine empire after few successes.
Banu Shayban was led by its chief, al-Muthanna bin Haritha. he was thinking of invading the Persian province, but he didn’t have men nor resource. He decided to ask for aid from the Caliph. He especially requested for Khalid. Khalid was still in Musaylima, he was ordered to direct his men towards Chaldea.
Battle of Chains, 633
Khalid, by the time he reached Khaffan, had gathered 10,000 men. Al-Muthanna joined with his 8,000. Khalid wrote a letter to Hormuz, who although undeterred by the letter forwarded it to the King Chosroes and requested reinforcements. Hormuz, on the other hand, set out to fight Khalid’s army. Hormuz reached al-Hafir and took possession of the spring. But it proved insignificant since Khalid just after his arrival launched an assault. He killed the commander, Hormuz, in one blow. The army of his was defeated too. Since the place was so narrow and the Persians were to chains the battle came to be associated with it. Arab army gained a large booty from opposition’s caravan.
The few left of army of Hormuz fled and they were chased by al-Muthanna. He confronted larger army now since the reinforcement had met them halfway. He again requested Khalid for aid. Khalid came at once and again using his provocative strategy beat the army.
Similarly, the King Chosroes tried again by sending a collective army at Walaja, but it was defeated too. Again, the Christian bloc of Bakr asked for men and resources from the King to fight the Muslims. They were provided with that; they lost too. The battle came to be known as Battle of Walaja and Ullays.
Conquest of Hira
Soon after his victory at Ullays, he turned northward towards Hira. The King had now fled leaving behind his Christian subjects. The subjects resisted for a while from behind their fortresses. Their courage as they had known about consistent Khalid’s victories. They surrendered, and a treaty was signed that came to be known as The Treaty of Hira. Hira was to remain Christian but Khalid or a Muslim would lead it and collect poll-tax. In turn he would provide protection.
Other Battles won
The Persians did little against the Arab invader. Al-Muthanna wanted to advance further and challenge the chief seat of that empire. The Caliph ordered Khalid to not do it. Instead, he would be ordered to move towards Christian Arab tribes dwelling beyond Hira to the West of the Euphrates.
The chief clan was Banu Taghlib; the same clan that taken part in Sajah’s supposed conquest. They had grown restless after seeing Hira fall. They continued pressing the Persian empire. They also gathered few other Christian tribes to rally behind them. Khalid defeated them in three consecutive battles at al-Anbar, Duma and Firaz. With this the conquest of Chaldea was complete and no other rebellion was expected. It is imperative to note here that Firaz was a border between Persian and Byzantine empire. Banu Taghlib had gained their support at the borders and fought the Muslims together. It is said the opposition’s army numbered 0.1 million but even that was defeated by Khalid.
Invasion of Syria
Syria was a land of several race, religions, and cultures. The tribes which lived on the Arab side of the border were more pagan than Christian. The Greek Orthodox Christians was an official religion.
The Ghasanid of Basra
Banu Ghassan was a Yemenite tribe that had migrated after the breach of Ma’rib Dam. The Ghassan established a kingdom in Syria. Over time, they came to assume the role of vassal state for Byzantine empire, as Chaldea did for Persian one. The vassals often fought too. The Ghassans were crumbling when Khusraw Pervez, emperor of Persia, invaded it in 619. Hercules, emperor of Byzantine, retook it and placed it under the Ghassans again.
Immediate cause and Abu Bakr’s reaction
Hercules had regained Asia Minor, Syria, and Egypt from Persians. But due to this he ran into debt and had to stop subsidies that he used to give to Bedouin tribes along the Arabian border. The alienated the tribes who now decided to throw their lot behind Muslims. Thus, the tribes of Judham and Quza’a played the same role that Shayban had in Hira conquest.
The relations between the Caliph and the Byzantine were strained since the Battle of Mutah in the days of the Prophet. It was for this reason that the Prophet had dispatched Usama’s expedition to Syrian border which Abu Bakr resumed.
Khalid bin Sa’ad’s Expedition
While the wars of Riddah were still going on, the Caliph decided to send a small army to keep an eye on Northern border that lay before Syria. Khalid was to keep an eye on movements of Byzantines and Arab tribes living there. He disregarded the order and launched an offensive which was decisively crushed. Khalid lost his son, but himself avoided death and fled to Madinah. Consequently, the Caliph decided to wage war against Byzantine in Syria. Since the armies were returning after winning Riddah war, he decided to divert them to Syrian border.
Abu Bakr dispatched the army in four successive detachments. It all happened in 634. The armies together numbered around 20,000. Unlike, other armies of Riddah, there were largely from Madinah. The Caliph instructed them well. Few excerpts from the instruction merit to be written here, for they present the manner of war that Islam allowed.
“O People! I have ten orders to give you, which you must observe loyally. Deceive none and steal from none. Betray none and disfigure no person killed on the battlefield. Do not kill any child, women, or aged man. Do not bark or burn the date
palms; nor cut down fruit trees nor destroy crops: do no slaughter cattle, flocks, or camels except for food. Do not kill monks and a hermit who you will come across in Syria.”
The Muslims got initial success and two detachments got full success in their advance. Hercules, on the other, formed an army of 100,000 soldiers to meet the Muslims. They were to be led by his brother, Theodorus. Abu Bakr sent an order to Khalid bin Walid to join the detachments in Syria. He left behind the administration in al-Muthanna’s hands and only gathered his men whereas al-Muthanna’s men would guard Hira. He joined Muslim forces near Damascus. He accepted as a supreme commander. He ordered the army to fall back to South till they reached a place on the Dead Sea, Ajnadayn. Here four detachments met plus Khalid bin Walid.
Thus, 40,000 men were now under the command of Khalid. The Hercules army met them at Ajnadayn. On 30th July 634 the battle started. Arabs charged so fiercely that Roman morale was shattered, and they fell back after a bloody opposition. Theodora ran away to the North. Muslims lot 3000 men but the victory opened Palestine to them. They invaded and conquered city after city till they reached Gaza. The news reached Abu Bakr when he was on his death-bed.
For complete Islamic history notes click here.