| 9 April 1241 | Mongol Empire, Poland, Bohemia, Moravia, Hungary, Holy Roman Empire [Mongol conquests (1206–1405)] | After sacking Kraków, a Mongol army led by Khaidu defeats the Poles, Silesians, and Teutonic Knights at Legnica in Poland. Grand Prince Henry II the Pious of Poland is killed. The Mongols next ravage Silesia and, when repulsed by the Bohemians, they go through Moravia into Hungary. |
| 9 April 1492 | Florence [births and deaths] | Lorenzo de' Medici the Magnificent, statesman and ruler of Florence 1453–92, dies in Careggi, near Florence, Italy (43). |
| 9 April 1548 | Peru [colonization] | The Spanish viceregal general Pedro de la Gasca defeats Gonzalo Pizarro at the battle of Jaquijahuana (Sacsahuaman) and executes him the following day, ending the conquistador regime in Cuzco against the authority of Lima in Spanish Peru. |
| 9 April 1555 | Papal States, Italy [political events] | The Italian churchman Marcello Cervini is elected as Pope Marcellus II following the death of Pope Julius III on 23 March. |
| 9 April 1626 | England [births and deaths] | Francis Bacon, Viscount St Albans, Baron Verulam, lord chancellor of England 1618–21, philosopher and man of letters, whose best-known works are Novum organum/New Engine and Essays, dies in London, England (65). |
| 9 April 1682 | North America [colonization] | René-Robert Cavelier, Sieur de la Salle, reaches the mouth of the Mississippi and takes possession of the entire Mississippi Valley for France, naming it Louisiana in honour of King Louis XIV of France. |
| 9 April 1806 | England [births and deaths] | Isambard Kingdom Brunel, British marine engineer who builds the first transatlantic steamer the Great Western (1838), and the Great Eastern (1858), the largest ship in the world for 40 years, born in Portsmouth, England (–1859). |
| 9 April 1865 | USA, Confederate States of America [American Civil War (1861–65)] | The Confederate Army of Northern Virginia under Robert E Lee surrenders to Union general Ulysses S Grant at Appomattox Courthouse, Virginia. |
| 9 April 1924 | Germany [political events] | Committees under the US financier Charles Dawes and British politician Reginald McKenna make reports on the World War I reparations issue; the Dawes Plan reduces Germany's debt to 1 million gold marks. |
| 9 April 1949 | USA [charities] | In the USA, the first telethon is presented by Milton Berle in aid of cancer research. It runs for 14 hours and raises more than $1 million. |
| 9 April 1980 | UK, Saudi Arabia, USA [television] | The British programme Death of a Princess, about the execution of a Saudi princess for adultery, causes a rift between Saudi Arabia and Britain. Its broadcast in the USA on 12 May attracts a record audience. |
| 9 April 1991 | Georgia, USSR [political events] | The Soviet republic of Georgia votes for independence from the USSR. |
| 9 April 1999 | Niger [political events] | Niger president Ibrahim Barre Mainassara is assassinated by members of his presidential guard at the airport in the capital, Niamey. A military government led by Daouda Wanke, head of the presidential guard, takes power. |
| 9 April 2005 | UK [political events] | Charles Prince of Wales, the heir to the British crown, marries his long-time companion Camilla Parker- Bowles, both divorcees, in a civil ceremony in Windsor, England, having postponed his wedding plans for a day to attend Pope John Paul II's funeral in the Vatican. |
