Dae Joyeong established Balhae (initially called Jin/Zhen) in the Songhua River region after the fall of Goguryeo, creating a new northeastern polity that would pursue recognition and trade with Tang China and Japan while managing relations with neighboring steppe and forest peoples.
By this year, Tang China and Balhae had established friendly relations, creating the diplomatic basis for later Tang investiture and regularized exchanges (tribute, titles, and trade).
Tang formally recognized Dae Joyeong as Balhae’s king, an early milestone in Balhae’s strategy of using Tang-style titles and institutions to stabilize its external position.
Tang bestowed a noble title on Balhae’s ruler (commonly rendered as “Prince of Commandery of Bohai/Parhae”), and Balhae’s official designation shifted from Jin to Bohai/Parhae (Balhae)—an important act of diplomatic investiture in the Tang-centered order.
Balhae dispatched its first recorded envoy delegation to Japan, initiating a long-running diplomatic and commercial relationship that Japanese sources portray as broadly amicable and strategically significant for both sides.
Balhae forces under commander Chang Munhyu carried out a naval assault on Dengzhou (Shandong), killing the Tang prefect—an episode showing Balhae’s maritime reach and intensifying confrontation with Tang amid wider regional rivalries.
After clashes in the early 730s, Balhae and Tang reestablished their alliance, in part shaped by the broader threat environment in Northeast Asia (including pressures from Khitan groups).
As part of a renewed diplomatic posture toward Tang, Balhae repatriated Tang sailors and civilians who had been detained, signaling de-escalation and a return to managed relations.
Balhae sent an envoy requesting Tang ritual codes and dynastic histories, reflecting deeper integration into Tang diplomatic culture and the practical transmission of statecraft models through diplomacy.
Tang formally elevated Balhae’s standing to that of a kingdom, enhancing Balhae’s prestige within the Tang-centric regional system and influencing how Balhae presented itself in external correspondence.
Across its history, Balhae maintained sustained diplomatic-commercial contact with Japan; Japanese records tally 34 Balhae missions to Japan and 13 Japanese missions to Balhae, underscoring the durability of the relationship even as its tone evolved over time.
Balhae was conquered by the Khitan (Liao), terminating Balhae’s independent diplomatic relations with Tang’s successor regimes, Japan, and steppe polities; Balhae elites and refugees dispersed, including movements toward the Korean peninsula.
Balhae's Diplomatic Relations with Tang China, Japan, and Steppe Polities (8th–10th centuries)
