Editing 1815 (section)

=== April ===
[[File:Congress of Vienna.PNG|thumb|[[June 9]]: The Final Act of the [[Congress of Vienna]] is signed.]]
[[File:Bodleian Libraries, Twelfth night or,- What you will now performing at the Theatre Royal Europe, with new scenery decorationscc.jpg|thumb|''[[Twelfth Night (print)|Twelfth Night]]''. Caricature of the Congress of Vienna by [[George Cruikshank]].]]
* [[April 10]]&ndash; [[Mount Tambora]] in the [[Dutch East Indies]]  [[1815 eruption of Mount Tambora|blows its top explosively during its peak eruption]], killing more than 92,000 people during week of activity from April 5 to April 12. The blast propels thousands of tons of aerosols ([[Sulfide]] gas compounds) into the [[stratosphere]], and the high level gases reflect sunlight, causing widespread cooling from a [[volcanic winter]]. During [[1816]], heavy rains fall arounde the world, snow falls in June and July in the [[Northern Hemisphere]], crops fail and widespread famine occurs. In later years, [[1816]] will become known as the ''[[Year Without a Summer]]''.
* [[April 21]] &ndash; In India, the eastern part of the former [[Garhwal Kingdom]] is joined with [[Kumaon division]], under the administration of the [[British Raj]].
* [[April 24]] &ndash; The [[Second Serbian Uprising]] against [[Ottoman Empire|Ottoman]] rule takes place in [[Takovo]], [[Ottoman Serbia]]. By the end of the year Serbia is acknowledged as a semi-independent state, temporarily achieving the ideals of the [[First Serbian Uprising]].