Battle of Marcellae: Constantine V sends a Byzantine expeditionary force (500 ships and 6,000 cavalry) to Thrace, and defeats the Bulgars around the Danube Delta and near the fortress city of Markeli (modern Bulgaria). Kormisosh is forced to accept a peace treaty, and confirms the existing frontier.[1] Due to the constant political crisis, the Bulgarian Empire is on the verge of destruction. Kormisosh is deposed during a palace coup and succeeded by Vinekh, a member of the Vokil clan.
Aistulf dies in a hunting accident, and is succeeded by Desiderius as king of the Lombards.[2] Ex-king Ratchis attempts unsuccessfully to seize the throne, but is opposed by Stephen II.
Galla Gaulo is deposed, blinded and exiled. He is succeeded by Domenico Monegario as the sixth doge of Venice. During his reign Venetian maritime traders become increasingly active.
Ibn al-Muqaffa', Muslim writer and thinker, is tortured at Basra (modern Iraq), on orders from Caliph al-Mansur. His limbs are severed and he is thrown, still alive, into a burning oven (approximate date).
Battle of Yongqiu: A Tang garrison (2,000 men), under Zhang Xun, successfully defend their fortress against the rebel army at Yongqiu. Zhang achieves a victory after a 4-month siege, and prevents the rebels from capturing the fertile Tang territory south of the Huai River.
February 5 – An Lushan declares himself emperor at Luoyang, establishing a new empire, called the Great Yan. He pushes on towards the primary Tang capital at Chang'an (now Xi'an). An decides to seize southern China, to cut off loyalist reinforcements. Meanwhile, numerous soldiers join the rebellion.
May – Emperor Xuan Zong hires 4,000 Muslim mercenaries to help defend Chang'an against the rebels. Loyalist forces take defensible positions in the mountain passes, but chancellor Yang Guozhong gives orders for them to leave their posts.
July 7[4][note 1]– An Lushan crushes the Tang troops at the Tong Pass, leaving the road to the capital wide open.
July 14 – Xuan Zong flees the capital of Chang'an (along with the imperial court) for Sichuan, as rebel forces advance through the Tongguan Pass toward the city. Meanwhile, An Lushan is ailing, perhaps with diabetes. He is nearly blind and suffers from extreme irascibility.
July 15 – Xuan Zong is ordered by his Imperial Guards to execute Yang Guozhong, by forcing him to commit suicide or face a mutiny. He permits his consort Yang Guifei to be strangled by his chief eunuch. An Lushan also has other members of the emperor's family killed.
August 12 – Xuan Zong abdicates the throne after a 44-year reign. He is succeeded by his son Su Zong, as emperor of the Tang Dynasty. He hires 22,000 Muslim mercenaries to reinforce his decimated army at Lingzhou.
November 19[7] – Tang General Fang Guan is defeated at Xianyang. The imperial forces consisted of two thousand oxcarts with cavalry and foot soldiers on two fronts, but the rebels took advantage of their upwind position and attacked with fire. Imperial forces killed or wounded numbered more than 40,000 men.
