Yazdegerd III

Yazdegerd III, who is almost the last living member of the House of Sasan, is the son of the Shahryar who was the son of Khosrau II.

The name of Yazdegerd's mother is unknown but she was from a non-aristocratic family.

The eight-year-old heir is hiding in Estakhr during the civil war in Persia, when on June 16, 632, he is crowned here as Shahanshah.

The Muslim conquest of Persia begins in his first year of reign.

The imperial commander (dux and candidatus) Sergius assembles a small detachment of soldiers (due to shortness of troops), and leads that mounted army from his base at Caesarea some one hundred and twenty-five kilometers south to the vicinity of Gaza.

He proceeds from here against an Arab force that is likely numerically superior and commanded by Abu Umamah al-Bahili.

The opposing forces meet on February 4, 634, at the village of Dathin not far from Gaza.

The imperial force is defeated and Sergius himself killed, together with three hundred of his soldiers.

According to the near-contemporary Doctrina Jacobi nuper baptizati, a seventh-century Greek Christian anti-Jewish polemical tract set in Carthage in 634 but written in Palestine sometime between 634 and 640, the Muslim victory is celebrated by the local Jews, who have been a persecuted minority within the Roman Empire.

The Muslim Arabs under Khalid defeat the Ghassanids at Al-Qaryatayn after the inhabitants resist his proposals.

His army conquers and plunder the city, before proceeding to capture other towns in the area.

The matter of Muhammad's succession at his death in 632 had taken place at the Saqifah, a roofed building used by the tribe called the Banu Sa'ida, of the faction of the Banu Khazraj tribe of the city of Medina.

Abu Ubaidah ibn al-Jarrah had been there along with Abu Bakr and Umar.

Umar had told Abu Ubaidah to stretch forth his hand for the caliphate, but he had refused and said to Abu Bakr to stretch forth his hand to take the pledge of alliance.

After the Ridda wars, when Abu Bakr had sent Khalid ibn al-Walid to Iraq to conquer it, he had sent four Muslim armies into the Levant, making Abu Ubaidah commander of one of them.

Emessa had been selected as his target and he had been ordered to move through the Tabuk region after the army of Sharjeel ibn Hassana.

He remains commander in chief of the Muslim army until Khalid arrives from Iraq to Syria in 634.

Abu Ubaidah is ordered by Khalid to remain where he is until the latter reaches the Ghassanid city of Bosra, where they meet in June.

Muslim forces under Khalid besiege the imperial and Christian Arab garrison (twelve thousand men) at Bosra.

After a few days, the fortress city surrenders, and Khalid imposes on the inhabitants a payment of tribute.

A Muslim Arab army under Khalid defeats the imperial forces (fifteen thousand men) and their Ghassanid allies in the Battle of Marj Rahit.

Large number of refugees from the region over which Khalid had recently operated had gathered here, and these refugees mingle with the crowds celebrating the joyous Ghassanid festival being held.

The Ghassanids, not unmindful of the danger which Khalid's entry into Syria poses for them, have positioned a strong screen of warriors on the route from Tadmur, below the pass; but this screen is scattered in a few minutes by a swift charge of the Muslim cavalry.

Although some Ghassanid resistance continues as the Muslims advance, it ceases once the main body of Muslims army reaches and attacks the town.

The Muslims raid the town of Marj Rahit.

After a little while, having collected a large amount of booty and a certain number of captives, Khalid pulls out of the town and camps outside.

The battle itself is not a major battle but it has some tactical importance to clean up the Muslim’s army rear so that the siege of larger cities can be laid in ease.

After the battle, Khalid sends a mounted column to the outskirts of Damascus to plunder the region.

Khalid bin Walid writes to Caliph Abu Bakr, informing him of the progress of his operations since his entry into Syria, and sends one-fifth of the spoils which had been won during the past few weeks.

Hardly had Bosra surrendered when an agent sent by Shurahbil to the region of Ajnadayn returns to inform the Muslims that the concentration of Roman legions is proceeding apace.

Soon they will have a vast army of ninety thousand imperial soldiers at Ajnadayn.

Khalid ibn Walid orders all the Muslim corps in Syria to concentrate at Ajnadayn and on July 30, 634, defeats the imperial army in the Battle of Ajnadayn.

Muslim Arabs under Khalid begin the siege of Damascus on August 21, 634.

Abu Bakr, opposed by unruly tribes, has led successful military campaigns across the Arabian peninsula, which he has united under Islam.

After the successful conquest of Iraq, Abu Bakr had sent his armies to invade Roman Syria, a main province of the Empire, dispatching three corps of about three thousand, later increased to about seventy-five hundred men each to start operations in southern and southeastern Syria.

Abu Bakr dies on August 23, 634 before he can witness the results of his undertakings.

The conquests he had initiated will be carried on by his successor, the caliph 'Umar I, who is the first caliph to call himself “commander of the faithful (amir al-mu'minin).

Khalid, operating in southern Iraq, is ordered to the aid of his fellow generals on the Syrian front, and on July 30, 634, the combined forces win a bloody victory against an imperial army at a place in southern Palestine that the sources call Ajnadain.

All of Palestine now lies open to the invaders.

Khalid is formally relieved (for unknown reasons) of high command by the new caliph, 'Umar, but he remains the effective leader of the forces facing Constantinople’s armies in Syria and Palestine.