Taizong launches a second invasion of Goguryeo in 647 but, failing to subjugate the Korean kingdom, again withdraws.

Traveling Buddhist monks have brought sugar crystallization methods to China.

During the reign of Harsha (r. 606–647) in North India, Indian envoys in Tang China had taught sugarcane cultivation methods after Emperor Taizong of Tang (r. 626–649) had made known his interest in sugar, and China soon establishes its first sugarcane cultivation in the seventh century.

Chinese documents confirm at least two missions to India, initiated in 647 CE, for obtaining technology for sugar-refining.

Taizong establishes a Chinese military government to pacify the former territory of Xueyantuo, which extends to the Altai Mountains in the west.

The site of Hafar Al-Batin is simply a route in the desert that pilgrims pass through on their way Mecca for Hajj.

At this time, there is no water available in this land, through which the pilgrims travel from Iraq to Mecca on a long route.

During the reign of Caliph Uthman ibn Affan, complaints of pilgrims reach Abu-Musa al-Asha'ari, a companion of the Islamic prophet Muhammad, who answers by digging for new wells along this route in the Al-Batin valley.

The name of Hafar Al-Batin is derived from this, which means "the hole of Al-Batin Valley".

Emperor Taizong sends a Chinese mission to study Indian techniques of sugar manufacturing at Bihar in the Ganges Valley.

Harsha dies in the year 647, having ruled for forty-one years.

His empire dies with him, the kingdom disintegrating rapidly into small states.

The succeeding period is very obscure and badly documented, but it marks the culmination of a process that had begun with the invasion of the Hunas in the last years of the Gupta Empire.

The Arabs had seized Cyrenaica and the eastern half of Tripolitania, along with Tripoli, in 642–643, their westward expansion halted only by an order from Caliph Umar.

In 647, however, Umar's successor Uthman orders Abdallah ibn Sa'ad to invade the Exarchate with twenty thousand men.

The Muslims invade western Tripolitania and advance up to the northern boundary of the imperial province of Byzacena.

Gregory confronts the Arabs on their return at Sufetula, but is defeated and killed.

Agapius of Hierapolis and some Syriac sources claim that he survived the defeat and fled to Constantinople, where he was reconciled with Constans, but most modern scholars accept the Arab chroniclers' account of his death in battle.

The Arab accounts also claim that the Muslims captured Gregory's daughter, who had fought at her father's side.

She was carried along back to Egypt as part of the booty, but she fell from her camel on the march and was killed.

After Gregory's death, the Arabs sack Sufetula and raid across the Exarchate, while the imperial forces withdraw to their fortresses.

Unable to storm the well-defended fortifications, and satisfied with the huge amounts of plunder they had made, the Arabs agree to depart in exchange for the payment of a heavy tribute in gold.

Despite the fact that the Arab raid is not followed up for some time, and the restoration of ties with Constantinople, imperial rule over Africa is shaken to its roots by Gregory's rebellion and the Arab victory.

The Berber tribes in particular shake off their allegiance to the Empire, and most of southern Tunisia seems to have slipped outside the control of Carthage.

The Book of Jin, an official Chinese historical text covering the history of the Jin Dynasty from 265 to 420, is compiled in China during the Tang Dynasty.

Its chief editor is the chancellor Fang Xuanling, who dies in this year as well.

Drawing mostly from official documents left from earlier archives, a few essays in volumes 1, 3, 54 and 80 have been composed by the Tang Dynasty's Emperor Taizong himself.

The contents of the Book of Jin, however, include not only the history of the Jin Dynasty, but also that of the Sixteen Kingdoms period, which was contemporaneous with the Eastern Jin Dynasty.

Tang general Ashina She'er re-establishes Tang control of Karasahr and …

…leads a military campaign against the Tarim Basin kingdom of Kucha in Xinjiang, a vassal of the Western Turkic Khaganate.