Tự Đức

Prince Nguyễn Phúc Hồng Bảo became the leader of a rebellion against Tự Đức, consisting of Confucian scholars who were angered that the family hierarchy had been dishonored (by passing over the eldest son) some remaining supporters of the Lê Dynasty (who many still considered the legitimate dynasty of Vietnam) as well as the usual peasants angry over Nguyễn taxation and the usual corrupt mandarins as well as the Roman Catholic missionaries and Christian converts who had been so persecuted by Minh Mạng and Thiệu Trị. With swift military force, Tự Đức suppressed the rebellion and was set to execute his brother, but was dissuaded by his mother, Dowager queen Từ Dũ, and Hồng Bảo killed himself in prison.

Emperor Tự Đức continued the policies of his predecessors, shutting Vietnam off from the outside world and refusing all efforts to modernize the country. Accounts of his personal life show a gentle and educated man, but his policies brought on conflict with Europe that Vietnam could not win. He oppressed all foreigners in Vietnam, especially the Christian community, who had tried to overthrow his grandfather, such as in the Lê Văn Khôi revolt, calling their religion a "perverse doctrine". The Christian mandarin Nguyễn Trường Tộ tried to convince Tự Đức that this was a suicidal policy, but he did not listen, confident that France was too involved with the chaos in Europe in 1848 to respond, but he was mistaken.

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  Death ceremony of Jean-Louis Bonnard. The lower right corner shows his body being cast in the water, where he was retrieved by Christians. In the upper right corner, Mgr Retord comes to the ceremony.
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  Portrait of Michael Hồ Đình Hy, Vietnamese mandarin official who was martyred for his Roman Catholic
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  Théophane Vénard, French Catholic missionary was executed by Tự Đức in 2/2/1861.\
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  Martyrdom of Augustin Schoeffler.

In 2018 Lê Minh Khải claimed that he found two instances where the Tự Đức Emperor had ordered the Chinese edition of several classic books on science and industry from the West to be read by the mandarins and soldiers of the country.[1] As an example he mentioned the book "Vạn Quốc Công Pháp" (萬國公法), a Chinese translation of The Elements of International Law, first published in 1836 by American lawyer Henry Wheaton, a book noted by many researchers to have made a profound contribution to the ideological transformation of the ruling elites in Qing China and Japan.[1] It is noted that the very slow adoption of the ideas from this work in the Nguyễn dynasty showed how slowly its elites adopted Western ideas and despite learning about Western ideas they proved to be unable or unwilling adopt them or adapt to them.[1]

France responded with a large military expeditionary force and attacked up from southern Vietnam. The Nguyễn army fought bravely for some time, but their antiquated weapons and tactics were no match for the French, who suffered more from the climate and disease than from enemy resistance. The fighting around Hanoi against the Black Flag[2] pirates ended with France victorious and China gave up their position as feudal master of Vietnam and recognized France as the ruling power over the region.

French and Spanish force capture of Saigon in 1859

To make matters worse, Emperor Tự Đức had to deal with renewed internal rebellions which had become commonplace for the Nguyễn Dynasty. There were literally hundreds of small rebellions and uprisings against Nguyễn rule. Ineffective attempts to enforce the ban on Christian missionaries were also the biggest source of trouble, including the execution of a Spanish bishop which was used to justify the French and Spanish invasion that led to the fall of Saigon. By an order of 1848 Tự Đức commanded all Vietnamese Catholic converts to renounce their religion, otherwise they would be branded on the face with the mark of a heretic and surrender all of their rights and privileges. This rallied most of the European powers against Vietnam, and Tự Đức by doing this had given up any hope of Vietnam gaining help as a victim from the outside world.

Gold lạng (Tael) of Tự Đức

When further rebellions broke out as the French were advancing on the capital, Tự Đức feared that his authority was crumbling. He preferred to make a deal with the French so that he could crush the rebellion since while France may demand humiliating concessions, the rebels would most likely depose and/or kill him. He signed away the southernmost of Vietnam, Cochinchina, to be a French colony and accepted the status of a French protectorate for his country. This caused a huge uproar, and many, such as the famous mandarin Trương Định, refused to recognize the treaty and fought on in defense of their country, denouncing Tự Đức for surrendering any part of their homeland.

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  Hoàng Diệu, who was the viceroy of Hanoi, committed suicide in 1882 after his defensive failure in Battle of Hanoi to France.
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  Phan Liêm, son of Phan Thanh Giản was captured by French colonel Francis Garnier in 1873 and released in 1874 after peace treaty.
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  Phạm Thận Duật who signed the Treaty of Huế (1884) and later he joined the anti-French resistance. He was the private tutor of future emperor Dục Đức and Đồng Khánh.
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  Đặng Huy Trứ, the reformist and the known for introduction of photography and western-model shipbuilding into Vietnam.