While Balhae found its footing, the other end of Eurasia was building a new order too

In a Korean timeline, 698 looks like a quiet year. Thirty years after Goguryeo fell, Dae Jo-yeong founded a state called Jin at the foot of Dongmo Mountain; in 713 a Tang investiture as King of Balhae Commandery fixed the name Balhae to it. Look across at the world column for the same century and it is far noisier: the Abbasid revolution of 750, the battle of Talas in 751, the founding of Baghdad in 762, Charlemagne’s coronation in 800. The two columns never mention each other, but set side by side they spell out one sentence. The eighth century was when great empires each shook once, and new orders rose in the space they left.

A state that began in an opening

Balhae began in an empire’s failure. After Goguryeo collapsed in 668, Tang set up the Protectorate General to Pacify the East to rule the old Goguryeo lands directly, but its grip on Liaodong did not hold. In 696 the Khitan leader Li Jinzhong rose in revolt at Yingzhou, and in the opening this tore in Tang’s northeastern control, Dae Jo-yeong led a body of Goguryeo refugees and Mohe groups eastward and founded a state. Had the empire been strong, no such state could have appeared; had the empire collapsed entirely, no such state would have needed the manoeuvring it did. Balhae’s place was the edge of an empire that was shaken but still standing.

Its diplomacy was therefore a balancing craft from the start. King Mu (r. 719–737) sent Jang Mun-hyu to attack the Tang port of Dengzhou in 732, cutting by force through the encirclement that Tang, Silla and the Heishui Mohe were forming around him. Yet the same king had opened relations with Japan in 727. Force and diplomacy were two hands of one body. His successor King Mun (r. 737–793) changed tack and imported Tang institutions wholesale: a central administration of three chancelleries and six boards, and a new capital at Sanggyeong Yongcheonbu laid out in imitation of Chang’an. In 762 Tang raised his title from King of Balhae Commandery to King of the State of Balhae — from the treatment due a provincial authority to the treatment due a country.

Under King Seon (r. 818–830) Balhae completed a provincial system of five capitals, fifteen prefectures and sixty-two districts, and expanded its territory considerably. That Tang sources came to call it Haedong Seongguk, the "flourishing land east of the sea," summarises its standing in this period. In the same decades Silla was beginning to fray in succession struggles between rival royal lines. The phrase "North–South States" rests on the fact that, for a stretch, these two existed at comparable weight.

The same century, a changing of hands at the other end

During the very decades Balhae was tuning its institutions, the west of Eurasia changed owners too. In 750 a rising led by Abu Muslim brought down the Umayyad caliphate and installed the Abbasids. This was not merely one dynasty replacing another. Where Umayyad rule had centred on an Arab elite, the Abbasids drew non-Arab Muslims, Persians above all, into the inside of government. When the caliph al-Mansur began building a new capital at Baghdad on the Tigris in 762, that was the physical declaration of the shift: the centre of gravity moved from the Mediterranean toward inner Asia.

The battle of Talas in 751 is one of the rare moments when these two worlds actually collided. On the Talas river in Central Asia, a Tang army under Gao Xianzhi was defeated by an Abbasid-led coalition. The consequence outlived the battle. The long-repeated account is that Tang prisoners taken there carried papermaking into the Islamic world — the starting point usually named for the route that took paper from Samarkand to Baghdad and eventually across the Mediterranean into Europe. How far a single encounter accounts for this is judged differently by different sources, and some hold that papermaking was already present in Central Asia.

For Tang, Talas marked the limit of its reach into the western regions; the real blow, though, came four years later and from inside. The An Lushan rebellion of 755, dragged out over eight years, left Tang’s central power permanently diminished. Regional military governors became warlords in all but name, a structure that ran on into the dynasty’s fall in 907 and the Five Dynasties period. Part of why Balhae could absorb Tang institutions without being absorbed by Tang is that the empire it was borrowing from never regained its former strength after these years.

A new crown at the western edge as well

Further west, another order was being assembled. At Tours-Poitiers in 732 Charles Martel halted a Muslim advance that had come north through Iberia, and on Christmas Day 800 his grandson Charlemagne received an imperial crown in Rome from Pope Leo III — the title of western Roman emperor revived after some three centuries. The coronation established the distinctly European arrangement in which secular power draws its legitimacy from religious authority, and set the terms of the emperor–pope relationship for the next thousand years.

King Mun’s investiture by Tang in 762 and Charlemagne’s coronation in 800 look formally alike: both are procedures for having one’s standing recognised by an older authority. But they ran in opposite directions. East Asian investiture was a matter of taking a place inside an imperial order that already existed; Charlemagne’s coronation was a matter of summoning a vanished empire back in order to stand in its place. In one century, at the two ends of Eurasia, two different ways of sourcing legitimacy hardened into form.

Why so little of Balhae survives

Balhae fell to the Khitan Liao in 926, and the trouble begins after that. Goryeo took in Balhae refugees but never organised Balhae’s history as its own; the Samguk sagi contains no annals for it. No history written by Balhae itself survives. What we know is reconstructed largely from Chinese records such as the Old and New Books of Tang, from Japanese diplomatic documents, and from excavation at the Sanggyeong site. When Yu Deuk-gong proposed the frame of the "North–South States" in his Balhaego (1784), treating Silla and Balhae together, he was making a late attempt to fill that gap.

This asymmetry in the record leaves one caution for reading any timeline. The eighth century is dense in the world column and sparse in the Korean one not because less happened north of the peninsula but because fewer people wrote it down and fewer of those writings survived. A blank in a timeline is sometimes not the absence of events but the absence of records.

The eighth century on a single line

Put the hundred years from 698 to 800 on one line and four unrelated events take the same shape. Balhae rose where Goguryeo had been removed; the Abbasids rose where the Umayyads had fallen; the military-governor system rose in the hole the An Lushan rebellion had punched; Charlemagne’s empire rose in the seat the western Roman empire had left empty. Eighth-century Eurasia was a century in which empires each came apart once, and the next order was assembled out of the pieces.

The resemblance is not causation. There is no basis for claiming direct influence between Balhae and the Abbasids. But the fact that several regions passed through a structurally similar moment at the same time is invisible when each is read alone. That some things appear only when placed side by side is the premise of this timeline.

At a glance

Year	Korean history	World history
698	Dae Jo-yeong founds Balhae	—
732	Balhae attacks Dengzhou	The battle of Tours-Poitiers
750	—	The Abbasid revolution
751	—	The battle of Talas
755	—	The An Lushan rebellion
762	King Mun invested as King of Balhae	Baghdad is founded
800	—	Charlemagne is crowned
926	Balhae falls to the Khitan	—

Read next

• Era guide: the North–South States
• Silla’s unification and the shadow of Tang
• While Goryeo fought the Mongols, Europe was sending crusades

References

• National Institute of Korean History, Woorihistory chronology, "The North–South States" — on Balhae’s founding, growth and foreign relations
• South Korean high-school world history curriculum — the expansion of the Islamic world, the rise and decline of Tang, the Frankish kingdom and Charlemagne
• Yu Deuk-gong, Balhaego (1784) — the late-Joseon work that treats Silla and Balhae together and proposes the "North–South States" frame

The facts follow the sources above; the comparisons and interpretation are our own.