Editing 1828 (section)

=== April–June ===
* [[April 11]] – The city of [[Bahía Blanca]] in modern-day [[Argentina]] is founded.
* [[April 18]] – Ornithologist [[Carl Julian (von) Graba]] lands in the little-studied [[Faroe Islands]] for a three-month visit to research the bird life.
* [[April 20]] – French explorer [[René Caillié]] becomes the first non-Muslim to enter [[Timbuktu]] and later return alive.
* [[April 26]] –
**Russia declares war on the Ottoman Empire, beginning the [[Russo-Turkish War (1828–1829)|Russo-Turkish War]].<ref>{{cite book |last1= Özavcı |first1= Hilmi Ozan |year= 2021|chapter= A New Era? The Vienna Order and the Ottoman World |title= Dangerous Gifts: Imperialism, Security, and Civil Wars in the Levant, 1798-1864|url= https://books.google.com/books?id=Lbo0EAAAQBAJ |publisher= Oxford University Press |pages= 128–129 |doi= 10.1093/oso/9780198852964.001.0001 |isbn= 9780198852964 |access-date= 31 July 2024}}</ref> 
**The Treaty of Commerce and Navigation is signed between [[Brazil]] and [[Denmark]], establishing diplomatic relations between the two countries.<ref>{{cite book|url=https://books.google.com/books?id=FZsAAAAAYAAJ&q=%22denmark+and+brazil%22&pg=PA717|title=British and Foreign State Papers|year=1829}}</ref>
* [[April 27]] – The [[London Zoo]] opens for members of the [[Zoological Society of London]] as the first scientific zoo in the United Kingdom.<ref>{{cite web|url=http://www.todayinsci.com/4/4_27.htm|title=April 27|work=Today in Science History|accessdate=2011-12-20}}</ref>
* [[May 9]] – The [[Sacramental Test Act 1828|Sacramental Test Act]] in the United Kingdom removes most prohibitions on [[Nonconformist (Protestantism)|nonconformist]]s and [[Catholics]] holding public office.<ref>{{cite journal|first=Richard A.|last=Gaunt|title=Peel's Other Repeal: The Test and Corporation Acts, 1828|journal=Parliamentary History|year=2014|volume=33|pages=243–262|doi=10.1111/1750-0206.12096 |url=http://eprints.nottingham.ac.uk/31450/ }}</ref>
* [[May 21]] – [[Antonio José de Sucre]] tries to invade [[Paraguay]], reaching the northern city of [[Fuerte Olimpo]], but the planned invasion is immediately cancelled. 
* [[May 26]] – The supposed [[feral child]] [[Kaspar Hauser]] is discovered in [[Nuremberg]], Germany.
* [[June 3]] – [[Gran Colombia–Peru War]]: Gran Colombia's President [[Simón Bolívar]] declares war on Peru.
* [[June 23]] – King [[Miguel I of Portugal]] overthrows his niece, Queen [[Maria II of Portugal|Maria II]], beginning the [[Liberal Wars]].