Mongkut concludes trade and friendship agreements with France and the US in 1856;

Chang Lo-hsing receives the title of “lord of the alliance” of the Nien in 1856, but he is far too weak to form a center.

Yang, as eastern king, has attempted to usurp much of the T'ien-wang's power prerogatives as Heavenly King, and in 1856 the resentful Hong orders Yang's execution.

Shi Dakai plots with the northern king Wei Changhui to kill Yang.

Not only is Yang put to death on September 2, 1856, but also his entire family and thousands of his adherents are destroyed.

When Shi objects to the slaughter, the northern king plots to kill him, but Shi discovers the plot and escapes, taking with him a large personal following and some of the most able Taiping commanders.

The Muslim-Chinese clash in central Yunnan develops into a slaughter of a great many Muslims in and around the provincial capital, K'un-ming, the following April.

This causes a general uprising of Yunnan Muslims, led by Tu Wen-hsiu, alias Sultan Sulayman.

Obtaining arms from the British authorities in Burma, Tu stages the Panthay Rebellion, a separatist movement of the Hui people and Chinese Muslims.

The British, seeking to extend their trading rights in China, find an excuse to renew hostilities in 1856 when some Chinese officials board the ship Arrow (a Chinese-owned ship registered in Hong Kong under British nationality and engaged in the opium trade) and lower the British flag.

The French join the British in this Second Opium War or Arrow War, using as their excuse the murder of a French missionary in the interior of China.

China’s Anglo-French War, or second Opium War, which begins in 1856, sees the foreign occupation and looting of Beijing.

Russia expands at Chinese expense.

The strict and repressive regime that had been imposed on Poland after the November Insurrection (1830-31) is substantially relaxed after Alexander II becomes emperor of Russia and king of Poland in 1855.

Conspiratorial societies that oppose any form of Russian rule in Poland remain active nevertheless, and gain support, particularly among students and other groups of urban youth.

Hermann von Helmholtz publishes the first of his seminal Handbook of Physiological Optics trilogy in 1856, providing empirical theories on spatial vision, color vision, and motion perception.

Russia's defeat in the Crimea forces the tsar to seek peace, affirmed in 1856 by the Treaty of Paris.

De jure Ottoman suzerainty over the principalities continues after the treaty, which abolishes the Russian protectorate and replaces it with a joint European guarantee.

The treaty also frees navigation on the Danube and forces Russia to cede part of southern Bessarabia, which includes control of the river's mouth, to Moldavia.

The active campaign for union of Wallachia and Moldavia begins in 1856.

The movement has the support of France, because many Romanian revolutionaries had taken refuge there after 1848 and lobbied Napoleon III to press for unification; Austria, Britain, and the Ottomans, however, oppose the unification effort, while Russia opts to let the Romanians decide.