Britain wars with Qing China after it cracks down on the opium trade; the defeat opens what China calls the 'century of humiliation'.
Representatives of the British Crown and many Māori chiefs signed the Treaty of Waitangi, New Zealand's founding document; differences between its English and Māori texts remain debated.
Victoria succeeds to the British throne; her reign of more than 63 years coincides with the height of the British Empire.
The Qing cede Hong Kong Island to Britain and open five treaty ports, the first of China's unequal treaties.
Potato blight triggers a famine that kills about a million people and drives more than a million to emigrate from Ireland.
A series of armed conflicts between the colonial government and Māori iwi, chiefly over land and sovereignty, which led to large confiscations of Māori land.
Michael Faraday discovers that a changing magnetic field induces an electric current, the principle behind generators and transformers.