...the attempted Ottoman–Egyptian invasion of Mani begins…

The British East India Company colony of the Straits Settlements is established in 1826 following the Anglo-Dutch Treaty of 1824, by which the Malay archipelago had been divided into a British zone in the north and a Dutch zone in the south.

This had resulted in the exchange of the British settlement of Bencoolen (on Sumatra) for the Dutch colony of Malacca and undisputed control of Singapore.

The Settlements are largely Chinese in population, with a tiny but important European minority.

The capital is George Town, the capital of Penang.

Tsar Nicholas I, after 1825, orders that male Jewish children be taken from their families at the age of twelve, undergo a period of training up to the age of eighteen, and then be sent for military service.

Aniline is first isolated from the destructive distillation of natural vegetable indigo, by Otto Unverdorben, a twenty-year-old German chemistry student.

He calls his discovery Crystallin.

Aniline will become important in the manufacture of dyes, plastics, and pharmaceuticals.

Ludwig van Beethoven puts the finishing touches on the String Quartet in C sharp Minor, Opus 131, the jewel in the crown of his late string quartets.  

In this year also, his Große Fuge of 1825, an immense double fugue, is universally condemned by contemporary critics.

However, critical opinion of the work will rise steadily from the beginning of the twentieth century.

The work is today considered among Beethoven's greatest achievements.

Peace has reigned in the Caucasus for thirteen years since the Treaty of Gulistan concluded the previous Russo-Persian War in 1813.

However, Fath 'Ali Shah, constantly in need of foreign subsidies, relies on the advice of British agents, who press him to reconquer the territories lost to Russia and pledge their support to military action.

The matter is decided in spring 1826, when a bellicose party of the Crown Prince, Abbas Mirza, prevails in Tehran and the Russian minister, Aleksandr Sergeyevich Menshikov, is placed under house arrest.

The position of Dost Mohammad Barakzai is secure after he assumes the title of Amir al-mu' minin (commander of the faithful).

In 1826 at Kabul, he decides to recover Peshawar from the Sikhs.

With Great Britain and Russia maneuvering for influence in Afghanistan, Dost Mohammad is forced to balance his nation between the two great powers.

He also seeks to recover territory lost from the central government's control during the civil war.

The British, feeling that Dost Mohammad is either hostile to them or unable to resist Russian penetration, move to take a direct role in Afghan affairs.

First they negotiate unsatisfactorily with Dost Mohammad, then they give military support to the deposed Afghan ruler, Shah Shoja', whom they have ensconced at Ludhiana.

French Neoclassicism influences Russian art and architecture, while Leo von Klenze develops Neo-Renaissance architecture in Germany.

The fall of the fortress at Mesolongion in the spring of 1826 ends with the massacre of thousands of Greek defenders by the Ottoman besiegers, giving the Ottoman forces control of western Greece and of the Gulf of Patras; ...

...the fall of Athens later in the year restores all of central Greece to Ottoman control.

The Balkan conflagration is close to extinction, at which point the powers of Western Europe intervene.