| 25 June 1080 | Holy Roman Empire [administration] | King Henry IV of Germany holds a council of bishops at Brixen which declares Pope Gregory VII to be deposed and elects Guibert, archbishop of Ravenna, as Pope Clement III. |
| 25 June 1183 | Holy Roman Empire, Italy [treaties] | By the Treaty of Constance, the Holy Roman Emperor Frederick I Barbarossa makes peace with the Lombard League of northern Italy, granting its cities self-government in return for an oath of allegiance. |
| 25 June 1243 | Italy [administration] | Sinibaldo dei Fieschi is elected Pope Innocent IV. |
| 25 June 1447 | Poland-Lithuania [political events] | Grand Prince Casimir (Kazimierz) IV Jagiellonczyk of Lithuania is crowned as King Casimir (Kazimierz) IV of Poland. It is now presumed that King Wladyslaw III (Warnenczyk) of Poland and Hungary was killed by the Ottoman Turks at Varna, Bulgaria, in 1444; his body was never recovered leading to tales of apparitions in different parts of Europe and Asia. |
| 25 June 1501 | Papal States, Naples, Italy, France, Spain [treaties] | Pope Alexander VI ratifies the secret Treaty of Granada (of 11 November 1500), which provides for the partition of the kingdom of Naples between France and Spain. He proclaims King Louis XII of France king of Naples and his son Cesare Borgia ‘Duke of Romagna’; Louis XII recognizes Cesare Borgia's conquests in the Romagna, northern Italy. |
| 25 June 1530 | Holy Roman Empire [political events] | At the Diet (legislative assembly) of Augsburg, Philip Melanchthon, who pleads the Protestant case while the German church reformer Martin Luther is under the Imperial Ban, presents the ‘Confession of Augsburg’ (a statement of the Protestant faith), agreed by seven princes and two imperial cities, to the Holy Roman Emperor Charles V. The conciliatory tone and content of this statement enrages the Zwinglians and annoys Luther. |
| 25 June 1608 | Habsburg Monarchy, Austria, Hungary, Bohemia, Holy Roman Empire [treaties] | The Holy Roman Emperor Rudolph II is compelled by the advance of an archducal army into Bohemia to cede Austria, Hungary, and Moravia to his brother Archduke Matthias of Austria and to promise him the succession to Bohemia in the Treaty of Lieben. |
| 25 June 1658 | India, Mogul Empire [wars] | Aurangzeb proclaims himself Mogul emperor, after imprisoning his sick father and slaughtering his two elder brothers, his son, and several nephews. |
| 25 June 1822 | Germany [births and deaths] | E(rnst) T(heodor) A(madeus) Hoffmann, German writer, composer, and painter, dies in Berlin, Germany (46). |
| 25 June 1852 | Spain [births and deaths] | Antonio Gaudí, Spanish architect known for his free-flowing forms and rich colours, born in Reus, Spain (–1926). |
| 25 June 1861 | Ottoman Empire [political events] | Sultan Abdul Mejid of the Ottoman Empire dies and is succeeded by his brother Abdul Aziz. |
| 25 June–1 July 1862 | USA [American Civil War (1861–65)] | After an inconclusive action at Seven Pines (Fair Oaks) near Richmond, Virginia, Confederate forces newly under the command of Robert E Lee mount a series of attacks on George B McClellan's superior Union army threatening the Confederate capital. In the Seven Days' Battle, at Mechanicsville, Gaines's Mill, Savage's Station, Frayser's Farm, and Malvern Hill, Lee drives McClellan back on his base at Harrison's Landing on the James River, and McClellan begins to evacuate the Peninsula altogether. |
| 25 June 1876 | USA [wars] | At the Battle of Little Bighorn, Sioux and Cheyenne warriors commanded by legendary chief Sitting Bull rout a force of US soldiers led by General George A Custer, killing Custer and over 200 of his soldiers. |
| 25 June 1885 | UK [administration] | Robert Cecil, Lord Salisbury, forms a Conservative ministry in Britain, with himself taking the position of foreign secretary as well as prime minister, Michael Hicks Beach chancellor of the Exchequer, and Richard Cross home secretary. |
| 25 June 1895 | UK [law and government] | Robert Cecil, Lord Salisbury, forms a unionist ministry in Britain with the former radical Joseph Chamberlain as colonial secretary. |
| 25 June 1918 | Russia [Russian Civil War (1918–20)] | Czech soldiers in Siberia, who were originally captured by the imperial Russian army, revolt. They seize the Trans-Siberian Railway in their attempt to reach Vladivostok, Russia, en route for Europe. |
| 25 June 1950 | North Korea, South Korea [Korean War (1950–53)] | Communist North Korean forces invade South Korea, with several armies advancing southwards. |
| 25 June 1953 | USA [television] | The Columbia Broadcasting System (CBS) begins the first regular television broadcasts in colour, in the USA. |
| 25 June 1975 | Mozambique, Portugal [decolonization] | Mozambique achieves independence from Portugal, with Samora Machel as president. |
| 25 June 1990 | USA [gay rights] | Active homosexuals are admitted to the rabbinate by the Central Conference of American Rabbis, but the Evangelical Lutheran Church suspends two churches that have ordained homosexuals. |
| 25 June 1991 | Croatia, Slovenia, Yugoslavia [Balkan conflicts (c. 1991–2000)] | The republics of Croatia and Slovenia declare independence from Yugoslavia. |
| 25 June 1993 | Canada [political events] | Kim Campbell, Progressive Conservative, becomes the first woman prime minister of Canada, following the resignation of Brian Mulroney. |
| 25 June 1997 | France [births and deaths] | Jacques Cousteau, French oceanographer who invented the aqualung, dies in Paris, France (87). |
| 25 June 1998 | USA [computing] | The US software company Microsoft releases its operating system Windows 98. |
| 25 June 1998 | China, USA [political events] | US president Bill Clinton arrives in China for a nine-day visit, the first by a US president since the Tiananmen Square massacre in 1989. |
