Muslim forces under Abu Ubaidah ibn al-Jarrah invade the Levant. Khalid sets out for Syria from Al-Hirah, taking with him half his army, about 8,000 strong. Battle of al-Qaryatayn: The Muslim Arabs under Khalid defeat the Ghassanids at Al-Qaryatayn, after the inhabitants resist his proposals. His army conquers and plunders the city, before proceeding to capture other towns in the area. Battle of Marj Rahit: A Muslim Arab army under Khalid defeats the Byzantine forces (15,000 men) and their Ghassanid allies. After the battle he sends a mounted column to the outskirts of Damascus, to plunder the region. Battle of Bosra: Muslim forces under Khalid besiege the Byzantine and Christian Arab garrison (12,000 men) at Bosra. After a few days the fortress city surrenders; Khalid imposes a payment of tribute on the inhabitants. August 23 – Abu Bakr dies at Medina and is succeeded by Umar I, who becomes the second caliph (khalifah) of the Rashidun Caliphate. During his rule, Umar conquers Syria, Persia, and Egypt in a "Holy War". September 19 – Siege of Damascus: Muslim Arabs under Khalid conquer Damascus as the first major city of the Byzantine Empire. Damascan refugees are given a guarantee of safety to retreat to Antioch. Battle of Maraj-al-Debaj: A Byzantine convoy of Damascan refugees (10,000 men) is slaughtered by a Muslim army near Antioch. The Mobile Guard (elite light cavalry) captures a great amount of brocade. Asia The Tuyuhun Kingdom is invaded by Chinese forces under Li Jing (Tang dynasty) during Emperor Taizong's campaign against Tuyuhun, resulting in the murder of their leader (khan) Murong Fuyun in 635. Tai Zong orders the construction of the Daming Palace in Chang'an. He builds the summer palace for his retired father, Emperor Gao Zu, as an act of filial piety. By topic Religion Aidan of Lindisfarne, Irish missionary, is summoned by King Oswald from Iona (Inner Hebrides) to establish a bishopric on the holy island of Lindisfarne, and reestablish Christianity in Northumbria (approximate date). Birinus, Frankish missionary, lands at the port of "Hamwic" (now in the St. Mary's area of Southampton), on his mission to reconvert the West Saxons in England. About this time, the St Mary's Church is founded. Sophronius becomes patriarch of Jerusalem. He sends synodical letters to Pope Honorius I and the Eastern patriarchs, explaining the Orthodox belief, by renouncing Monothelitism. Births Athanasius II Baldoyo, patriarch of Antioch (d. 686) Chad of