Emperor Xuanzong of Tang in the context of "Emperor Taizong of Tang"

The An Lushan rebellion was a civil war in China that lasted from 755 to 763, at the approximate midpoint of the Tang dynasty (618–907). It began as a commandery rebellion attempting to overthrow and replace the Tang government with the rogue Yan dynasty. The rebels succeeded in capturing the imperial capital Chang'an after the emperor had fled to Sichuan, but eventually succumbed to internal divisions and counterattacks by the Tang and their allies. The rebellion spanned the reigns of three Tang emperors: Xuanzong, Suzong, and Daizong.

On 16 December 755, An Lushan, the jiedushi of the Taiyuan Commandery, mobilized his army and marched to Fanyang. An Lushan led the rebellion for two years before he was assassinated by his son An Qingxu. Two years after An Qingxu's ascension, Shi Siming, the governor of Pinglu Commandery and a close ally of An Lushan, killed An Qingxu and usurped the leadership. Shi Siming ruled for two years, but was in turn killed by his own son Shi Chaoyi, who ruled for another two years until the Yan dynasty fell to Tang forces on 17 February 763. There were also other anti-Tang rebel forces, especially those in An Lushan's base area in Hebei, as well as Sogdian forces and other opportunist parties who took advantages of the chaos.

Yan (Chinese: 燕; pinyin: Yān), also known as the Great Yan (Chinese: 大燕; pinyin: Dà Yān), was a dynastic state of China established in 756 by the former Tang general An Lushan, after he rebelled against Emperor Xuanzong of Tang in 755. The state collapsed in 763 with the death of An Lushan's former subordinate Shi Chaoyi (son of Shi Siming), who was the last person to claim the title as emperor of Yan.

Emperor Suzong of Tang (yihai day, 711 – 16 May 762; r. 756 – 762), personal name Li Heng, né Li Sisheng (李嗣升), known as Li Jun (李浚) from 725 to 736, known as Li Yu (李璵) from 736 to 738, known briefly as Li Shao (李紹) in 738, was an emperor of the Chinese Tang dynasty and the son of Emperor Xuanzong.

Suzong ascended the throne after his father fled to Sichuan during the An Lushan Rebellion in 756; Li Heng himself had fled in the opposite direction, to Lingwu, where he was declared emperor by the army. Much of Emperor Suzong's reign was spent in quelling the aforementioned rebellion, which was ultimately put down in 763 during the reign of his son Emperor Daizong.

An Lushan (Chinese: 安祿山; pinyin: Ān Lùshān; 20th day of the 1st month (19 February) 703 – 29 January 757) was a Chinese military general and rebel leader during the Tang dynasty and is primarily known for instigating the An Lushan rebellion which devastated China and killed millions of people.

An Lushan was of Sogdian and Göktürk origin, at least by adoption. He rose to prominence as a general by defending the northeastern Tang frontier from the Khitans and other threats. Through his frequent visits to Chang'an, the Tang capital, An Lushan managed to gain favour with Emperor Xuanzong of Tang and Chancellor Li Linfu. By 751, he had been appointed military governor over three prefectures. After the death of Li Linfu in 753, An Lushan's rivalry with General Geshu Han and Chancellor Yang Guozhong created military tensions within the empire.

Chinese Esoteric Buddhism refers to traditions of Tantra and Esoteric Buddhism that have flourished among the Chinese people. The Tantric masters Śubhakarasiṃha, Vajrabodhi and Amoghavajra, established the Esoteric Buddhist Zhenyan (Chinese: 真言, "true word", "mantra") tradition from 716 to 720 during the reign of Emperor Xuanzong of Tang. It employed mandalas, mantras, mudras, abhiṣekas, and deity yoga. The Zhenyan tradition was transported to Japan as Tendai and Shingon Buddhism by Saichō and Kūkai, as well as influencing Korean Buddhism and Vietnamese Buddhism. The Song dynasty (960–1279) saw a second diffusion of Esoteric texts. Esoteric Buddhist practices continued to have an influence into the late imperial period and Tibetan Buddhism was also influential during the Yuan dynasty period and beyond. In the Ming dynasty (1368–1644) through to the modern period, esoteric practices and teachings became absorbed and merged with the other Chinese Buddhist traditions to a large extent.

In Chinese these traditions are also termed Mìjiào (Chinese: 密教; Esoteric Teaching), Mìzōng (密宗; "Esoteric Tradition") or Tángmì (唐密; "Tang (Dynasty) Esoterica").

Qingliang Chengguan (Chinese: 澄觀; pinyin: Chéngguān; Korean: Jinggwan; Japanese: Chōgan, 738–839 or 737-838 CE), was an important scholar-monk and patriarch of the Huayan school of Chinese Buddhism also known as Huayan pusa (bodhisattva Avatamsaka) and Qingliang Guoshi (Imperial Preceptor "Clear and Cool", Clear and Cool is a name for Mount Wutai).

Chengguan is most widely known for his extensive commentaries and sub-commentaries to the Avataṃsaka Sūtra (Huayan jing), as well as for his translation of a new Gandhavyuha sutra version, together with the Indian monk Prajña. Chengguan's commentaries on the Avataṃsaka quickly became one of the authoritative sources for Huayan doctrine. Chengguan lived through the reigns of nine emperors and was an honored teacher to seven emperors starting with Xuanzong (玄宗) until Wenzong (文宗). Chengguan was also the teacher of the influential Huayan patriarch Zongmi.

Empress Wei (Chinese: 韋皇后; pinyin: Wéi Huánghòu; personal name unknown; died July 21, 710) was an empress consort of the Chinese Tang dynasty. She was the second wife of Emperor Zhongzong, who reigned twice, and during his second reign, she tried to emulate the example of her mother-in-law Wu Zetian and seize power. She was de facto in charge of the governmental affairs during her husband's reign, though she was not formally regent. Emperor Zhongzong's death in 710 — a death traditionally believed to be a poisoning she carried out together with her daughter Li Guo'er the Princess Anle — made her the empress dowager, and she took formal power as regent de jure during the minority of Emperor Shang of Tang. After a reign of seventeen days as regent, she was overthrown and killed in a coup led by Emperor Zhongzong's nephew Li Longji (the later Emperor Xuanzong) and Emperor Zhongzong's sister Princess Taiping.

The Battle of Changping (長平之戰) was a military campaign during the Warring States period of China that was fought between the two strongest military powers of the central plains, the State of Qin, State of Zhao northwest of present-day Gaoping). After a bitter two-year stalemate stretching 262 to 260 BC, the battle ended in a decisive victory for Qin forces. A vast majority of Zhao captives were ruthlessly executed, an unrecoverable loss of manpower and strategic reserve that permanently crippled the State of Zhao.

It is known as the greatest and longest battle of human antiquity. Infamous for being one of the deadliest battles in human history, several hundred thousand soldiers were buried alive in the aftermath. The main historical records for the events of this period is sourced from the Records of the Grand Historian, written more than a century later, which estimated roughly 450,000 dead on the Zhao side and 250,000 dead on the Qin side. Emperor Xuanzong of Tang (685–762) later built a temple over a collection of some of the human remains, and scattered bones and mass graves continue to be discovered on the site today.