In the mid-600s, Silla sought Tang help against its rivals Baekje and Goguryeo. Kim Chun-chu (the future King Muyeol) helped build this alliance, which later made large joint campaigns possible. This diplomatic shift set the stage for Silla’s unification wars.
Kim Chun-chu became King Muyeol of Silla, bringing pro-Tang policy to the center of government. Under his reign, Silla coordinated strategy with Tang and prepared to strike Baekje first. His accession helped turn Silla’s diplomacy into military action.
Silla forces led by Kim Yu-sin defeated Baekje’s army under General Gyebaek at Hwangsanbeol. The victory removed Baekje’s main battlefield defense and opened the way to the capital area. It was a critical step toward Baekje’s collapse later that year.
Tang emperor Gaozong sent Su Dingfang with a major expedition to attack Baekje in coordination with Silla. Tang forces crossed the Yellow Sea and advanced on Baekje’s capital region. The joint Silla–Tang operation showed how the alliance could project overwhelming force.
After Silla and Tang forces reached the Baekje capital Sabi (near modern Buyeo), Baekje’s court fled and then surrendered. King Uija’s capture ended Baekje as an independent kingdom, though resistance continued. The fall of Sabi shifted the war from conquest to occupation and suppression of loyalists.
After Baekje’s capital fell, loyalist forces regrouped and tried to restore the kingdom. Key strongholds included Juryuseong and Imjonseong, and the movement sought outside support. This prolonged fighting showed that conquest did not immediately equal control.
After Muyeol’s death, his son Munmu became king and continued the campaigns against Goguryeo and the remaining pockets of resistance. Leadership continuity mattered because Silla was coordinating large operations with Tang while also managing conquered territory. Munmu later became a central figure in both unification and the break with Tang.
With defeat at sea and continued pressure on land, the restoration stronghold at Juryuseong surrendered. Nearby fortresses soon capitulated as well, closing the main three-year resistance. This made Silla and Tang free to focus more fully on Goguryeo and postwar control.
Baekje restoration forces and Yamato Japan attempted to break the siege and revive Baekje, but Silla–Tang forces won a decisive naval victory at Baekgang (also known as Hakusukinoe in Japan). The defeat forced Yamato to withdraw from major involvement on the peninsula. It also crippled the Baekje restoration movement’s ability to continue large-scale war.
In 668, the Tang–Silla coalition defeated Goguryeo, ending the Three Kingdoms period’s major rival to Silla. After the conquest, Tang established the Protectorate General to Pacify the East (Andong Protectorate) at Pyongyang to administer former Goguryeo territory. This postwar arrangement created new friction, because Tang governance now overlapped with Silla’s ambitions.
After Baekje and Goguryeo were conquered, Tang attempted to tighten its administrative control in Korea through commanderies and protectorate structures. Silla resisted and allied with Baekje and Goguryeo loyalists against Tang forces. The conflict marked a shift from alliance warfare to a struggle over who would rule the peninsula.
Silla defeated Tang forces at the Battle of Maeso, a key turning point in the Silla–Tang War. The battle showed Silla could win against Tang armies and helped slow Tang efforts to reassert control south of the Taedong River. It also strengthened Silla’s position in negotiations and follow-on campaigns.
By 676, Silla had driven Tang out of most of the Korean Peninsula, leaving Tang control largely north of the Taedong River. This outcome is commonly treated as the end of Silla’s unification wars because it secured Silla rule over most of the peninsula’s southern and central regions. The result is often described as the start of the Unified Silla period, even though later states in the north emerged beyond Silla’s control.
Silla's Unification Wars (660–676)