Al-Muazzam Isa vs Li Chun

Al-Muazzam Isa, as Ayyubid ruler of Damascus, participated in the defense against the Fifth Crusade. The Crusaders besieged Damietta in the Nile Delta. Al-Muazzam Isa's forces were unable to prevent the city's fall in 1219, leading to a temporary Crusader occupation.

Al-Muazzam Isa, alongside his brother Sultan Al-Kamil of Egypt, negotiated the end of the Fifth Crusade. The treaty restored Damietta to the Ayyubids in exchange for a truce and the Crusaders' withdrawal from Egypt. This secured Ayyubid control over the region.

Al-Muazzam Isa engaged in a power struggle with his brother Sultan Al-Kamil of Egypt. He allied with the Khwarezmian prince Jalal al-Din against Al-Kamil. This internal Ayyubid conflict weakened the dynasty and allowed Crusader states to regain territory.

Al-Muazzam Isa died in Damascus, likely from natural causes. His death ended his rivalry with Al-Kamil and allowed the Egyptian sultan to consolidate Ayyubid power. His son An-Nasir Dawud succeeded him but was later deposed by Al-Kamil.

Li Chun launched a series of military campaigns to reassert central control over rebellious fanzhen. He defeated the warlords of Sichuan, Zhenhai, and other provinces, reducing their autonomy and restoring imperial authority.

Li Chun's forces defeated the powerful Zhaoyi fanzhen, whose military governor had rebelled. This victory was a major achievement of the Yuanhe Restoration, demonstrating the Tang court's renewed military strength.

After a long campaign, the Chengde fanzhen submitted to central authority. This was the last major fanzhen to be brought under control during Li Chun's reign, marking the peak of the Yuanhe Restoration.

Li Chun died in 820, possibly poisoned by eunuchs. His death ended the Yuanhe Restoration, and subsequent emperors were unable to maintain the central authority he had reestablished.