Choe U vs Wanyan Zongbi

Choe U succeeded his father Choe Chung-heon as head of the military regime, maintaining control over Goryeo through puppet kings. He continued the family's authoritarian rule, suppressing any opposition.

Choe U refused Mongol demands for submission and tribute, leading to a series of Mongol invasions. His defiance prolonged the war but ultimately resulted in devastating campaigns against Goryeo.

Choe U moved the Goryeo court to Ganghwa Island to escape Mongol attacks, using the island's natural defenses. This allowed the regime to continue resistance but left the mainland vulnerable to Mongol raids.

Choe U died, and his son Choe Hang succeeded him. However, internal divisions weakened the regime, leading to its eventual collapse in 1258 and the restoration of royal authority under Mongol influence.

Wanyan Zongbi led a major Jin invasion of Southern Song territory, advancing deep into the south. He captured the Song capital of Hangzhou temporarily but was eventually repelled by Song forces.

Wanyan Zongbi's Jin army was defeated by Yue Fei's Song forces at Yancheng. This battle was a major setback for Jin and demonstrated the effectiveness of Yue Fei's military tactics.

Wanyan Zongbi played a key role in negotiating the Treaty of Shaoxing with the Southern Song. The treaty established the Huai River as the border and required Song to pay tribute to Jin, ending major hostilities.

Wanyan Zongbi demanded the execution of Yue Fei as part of the peace settlement. The Song court complied, executing Yue Fei, which removed a major obstacle to Jin's security.

Wanyan Zongbi died, having been one of the most influential Jin generals. His campaigns and diplomacy shaped Jin-Song relations for decades.