| 10 April 879 | Carolingian Empire [political events] | Louis II the Stammerer, King of the Franks, dies. He is succeeded by his sons, Louis III and Carloman, after an abortive invasion by Louis of Saxony who tries to seize the kingdom. |
| 10 April 1281 | Rome, Byzantine Empire [political events] | Pope Martin IV, under the influence of Charles of Anjou, King of Sicily, excommunicates the Byzantines and renounces the union of 6 July 1274. |
| 10 April 1302 | France [administration] | King Philip IV of France holds the first known meeting of the Estates General (assembly containing representatives of the three estates, aristocracy, clergy, and commons) in Paris, France, to rally national opinion against Pope Boniface VIII. |
| 10 April 1525 | Prussia, Poland-Lithuania [political events] | Albert von Hohenzollern, Grand Master of the Teutonic Knights (a German military Christian order), converts the Prussian lands of his order into the Lutheran duchy of Prussia, of which he will be duke as a vassal of King Sigismund I of Poland. |
| 10 April 1533 | Denmark-Norway [political events] | King Frederick I of Denmark-Norway dies, precipitating a religious and succession crisis that leads to a three-year civil war, ‘the Count's War’. The Danish diet, dominated by Catholic bishops and nobles, refuses to accept his Lutheran son Christian, stadtholder (provincial governor) of Schleswig-Holstein, as king, favouring his other (infant) son Hans. |
| 10 April 1599 | France [political events] | Gabrielle d'Estrées, Duchess of Etampes, the mistress of King Henry IV of France, de-facto queen, and sponsor of his conversion to Catholicism and appointment of Maximilien de Béthune, Marquis Rosny (later Duke of Sully) as superintendent of finance, dies. |
| 10 April 1827 | UK [law and government] | The Tory foreign secretary, George Canning, becomes prime minister of Britain, forming a government of liberal Tories and moderate Whigs. |
| 10 April 1832 | Ottoman Empire, Egypt, Ottoman Empire [political events] | The Ottoman Empire declares war on Mehmet Ali, its representative in Egypt, who is in effect independent. He is demanding the Ottoman province of Syria as his reward for aiding the Ottoman Empire in the Greek War of Independence. |
| 10 April 1864 | Austrian Empire, Mexico, France [political events] | Archduke Maximilian of Austria accepts the title offered by Napoleon III of emperor of Mexico, following French military victories there in an attempt to enforce the payment of European debts. France wishes to establish a liberal, Catholic empire in Mexico. |
| 10 April 1919 | Romania, Hungary [wars] | Romania invades Hungary to prevent it attempting to retake disputed Transylvania. |
| 10 April 1932 | Germany [elections] | Paul von Hindenburg is re-elected German president on the second ballot. |
| 10–13 April 1940 | UK, Germany, Norway [World War II (1939–45)] | Several naval battles are fought between British and German forces off the port of Narvik in northern Norway; ten German destroyers (from a total of twenty) are sunk. Their loss, added to the loss of three (out of eight) cruisers in the invasion of Norway itself severely weakens the German navy's offensive capability. |
| 10 April 1966 | England [births and deaths] | Evelyn Waugh, English satirical novelist, dies in Combe Florey, near Taunton, Somerset, England (62). |
| 10–11 April 1994 | Bosnia-Herzegovina, Federal Republic of Yugoslavia [Balkan conflicts (c. 1991–2000)] | NATO (the North Atlantic Treaty Organization) makes air strikes on Serbian posts near the United Nations (UN) ‘safe area’ of Goradze in Bosnia-Herzegovina, but subsequently (17 April) Goradze falls to Serb forces. |
| 10 April 1998 | Northern Ireland [diplomacy] | Ireland, Britain, and the political parties in Northern Ireland reach a peace agreement over Northern Ireland involving the devolution of a wide range of executive and legislative powers to a Northern Ireland Assembly. |
| 10 April 2001 | Netherlands [medicine] | The Netherlands becomes the first country in the world to legalize euthanasia as the upper house of parliament gives final endorsement to legislation. |
