On this day: 26 July

First Fitna: In the Battle of Siffin, troops led by Ali ibn Abu Talib clash with those led by Muawiyah I.

Rout of an alliance of Christian troops from Navarre and Léon against the Muslims at the Battle of Valdejunquera.

Krishnadevaraya ascends to the throne as Emperor of Vijayanagara, marking the beginning of the regeneration of the Vijayanagara Empire.

Francisco Pizarro González, Spanish conquistador, is appointed governor of Peru.

The Knights Hospitaller surrendered the Castello of Gozo to the Ottoman Empire following a brief siege, leading to the mass enslavement and dispersal of the Gozitan population.

Plakkaat van Verlatinghe (Act of Abjuration): The northern Low Countries declare their independence from the Spanish king, Philip II.

During the Bavarian Rummel the rural population of Tyrol drove the Bavarian Prince-Elector Maximilian II Emanuel out of North Tyrol with a victory at the Pontlatzer Bridge and thus prevented the Bavarian Army, which was allied with France, from marching as planned on Vienna during the War of the Spanish Succession.

The office that would later become the United States Post Office Department is established by the Second Continental Congress. Benjamin Franklin of Pennsylvania takes office as Postmaster General.

On the orders of Catherine the Great the first of tens of thousands of Greek and Armenian Christians were removed from Crimea and resettled in Pryazovia.

New York ratifies the United States Constitution and becomes the 11th state of the United States.

The Swedish–Norwegian War begins.

José de San Martín arrives in Guayaquil, Ecuador, to meet with Simón Bolívar.

First day of the three-day Battle of Dervenakia, between the Ottoman Empire force led by Mahmud Dramali Pasha and the Greek Revolutionary force led by Theodoros Kolokotronis.

The University of Wisconsin–Madison is established by Nelson Dewey, first Governor of Wisconsin.

American Civil War: George B. McClellan assumes command of the Army of the Potomac following a disastrous Union defeat at the First Battle of Bull Run.

Premiere of Richard Wagner's opera Parsifal at Bayreuth.

L. L. Zamenhof (pictured) published Unua Libro, the first publication to describe Esperanto, a constructed international language.

In Buenos Aires, Argentina the Revolución del Parque takes place, forcing President Miguel Ángel Juárez Celman's resignation.

France annexes Tahiti.

United States Attorney General Charles Joseph Bonaparte issues an order to immediately staff the Office of the Chief Examiner (later renamed the Federal Bureau of Investigation).

Emmy Noether's paper, which became known as Noether's theorem was presented at Göttingen, Germany, from which conservation laws are deduced for symmetries of angular momentum, linear momentum, and energy.

Spanish Civil War: Germany and Italy decide to intervene in the war in support for Francisco Franco and the Nationalist faction.

Spanish Civil War: End of the Battle of Brunete with the Nationalist victory.

World War II: The Potsdam Declaration is signed in Potsdam, Germany.

Aloha Airlines begins service from Honolulu International Airport.

Cold War: U.S. president Harry S. Truman signs the National Security Act of 1947 into United States law creating the Central Intelligence Agency, United States Department of Defense, United States Air Force, Joint Chiefs of Staff, and the United States National Security Council.

U.S. president Harry S. Truman signs Executive Order 9981, desegregating the military of the United States.

King Farouk of Egypt abdicates in favor of his son Fuad.

Cold War: Fidel Castro leads an unsuccessful attack on the Moncada Barracks, thus beginning the Cuban Revolution. The movement took the name of the date: 26th of July Movement

The Battle of the Samichon River, the last engagement of the Korean War, ended a few hours before the signing of the Korean Armistice Agreement.

Following the World Bank's refusal to fund building the Aswan Dam, Egyptian leader Gamal Abdel Nasser nationalizes the Suez Canal, sparking international condemnation.

Explorer program: Explorer 4 is launched.

The Organisation for Economic Co-operation and Development votes to admit Japan.

Syncom 2, the world's first geosynchronous satellite, is launched from Cape Canaveral on a Delta B booster.

After coming second to Nguyễn Văn Thiệu in a rigged presidential election, Trương Đình Dzu was jailed by a South Vietnamese military court for illicit currency transactions.

Apollo program: Launch of Apollo 15 on the first Apollo "J-Mission", and first use of a Lunar Roving Vehicle.

Greek Prime Minister Konstantinos Karamanlis forms the country's first civil government after seven years of military rule.

The National Assembly of Quebec imposes the use of French as the official language of the provincial government.

The Americans with Disabilities Act of 1990 is signed into law by President George H. W. Bush.

Kargil conflict officially comes to an end. The Indian Army announces the complete eviction of Pakistani intruders.

Hillary Clinton (pictured) became the first female nominee for president of the United States by a major political party at the Democratic National Convention in Philadelphia.

Solar Impulse 2 becomes the first solar-powered aircraft to circumnavigate the Earth.