On this day: 17 August

Byzantine–Bulgarian wars: The Bulgarians defeated Byzantine forces at the battle of the Gates of Trajan near present-day Ihtiman, with Emperor Basil II barely escaping.

Georgenberg Pact: Ottokar IV, Duke of Styria and Leopold V, Duke of Austria sign a heritage agreement in which Ottokar gives his duchy to Leopold and to his son Frederick under the stipulation that Austria and Styria would henceforth remain undivided.

Karl Topia, the ruler of Princedom of Albania, forges an alliance with the Republic of Venice, committing to participate in all wars of the Republic and receiving coastal protection against the Ottomans in return.

Konrad Bitz, the Bishop of Turku, marks the date of his preface to Missale Aboense, the oldest known book of Finland.

Cesare Borgia, son of Pope Alexander VI, becomes the first person in history to resign the cardinalate; later that same day, King Louis XII of France names him Duke of Valentinois.

Eighty Years' War: Siege of Antwerp: Antwerp is captured by Spanish forces under Alexander Farnese, Duke of Parma, who orders Protestants to leave the city and as a result over half of the 100,000 inhabitants flee to the northern provinces.

Scanian War: Swedish forces defeated Danish troops at the Battle of Halmstad.

Austro-Turkish War of 1716–18: The month-long Siege of Belgrade ends with Prince Eugene of Savoy's Austrian troops capturing the city from the Ottoman Empire.

Ioan Giurgiu Patachi becomes Bishop of Făgăraș and is festively installed in his position at the St. Nicolas Cathedral in Făgăraș, after being formally confirmed earlier by Pope Clement XI.

Pope Benedict XIV, previously known as Prospero Lambertini, succeeds Clement XII as the 247th Pope.

Classical composer Luigi Boccherini receives a pay rise of 12,000 reals from his employer, the Infante Luis, Count of Chinchón.

The Vietnamese Catholics report a Marian apparition in Quảng Trị, an event which is called Our Lady of La Vang.

Robert Fulton's North River Steamboat leaves New York City for Albany, New York, on the Hudson River, inaugurating the first commercial steamboat service in the world.

The Finnish War: The Battle of Alavus is fought.

American Civil War: Major General J. E. B. Stuart is assigned command of all the cavalry of the Confederate Army of Northern Virginia.

American Indian Wars: The Dakota War of 1862 begins in Minnesota as Dakota warriors attack white settlements along the Minnesota River.

American Civil War: Battle of Gainesville: Confederate forces defeat Union troops near Gainesville, Florida.

The Grand Duchy of Baden announces its withdrawal from the German Confederation and signs a treaty of peace and alliance with Prussia.

The premiere of Götterdämmerung by Richard Wagner (pictured) closed the first Bayreuth Festival.

The first public performance of the Dominican Republic's national anthem, Himno Nacional.

Pike Place Market (pictured), one of the oldest continuously operated public farmers' markets in the U.S. and a popular tourist attraction, opened in Seattle, Washington.

World War I: Ignoring orders to retreat, Hermann von François led a successful counterattack defending East Prussia at the Battle of Stallupönen and scored the first German victory in the Eastern Front.

World War I: Romania signs a secret treaty with the Entente Powers. According to the treaty, Romania agreed to join the war on the Allied side.

Animal Farm, George Orwell's satirical allegory of Soviet totalitarianism, was first published.

The independence of Indonesia was proclaimed, igniting a revolution against the Dutch Empire.

Evacuation of Manchukuo: At Talitzou by the Sino-Korean border, Puyi, then the Kangde Emperor of Manchukuo, formally renounces the imperial throne, dissolves the state, and cedes its territory to the Republic of China.

The Radcliffe Line, the border between the Dominions of India and Pakistan, is revealed.

Pioneer 0, America's first attempt at lunar orbit, is launched using the first Thor-Able rocket and fails. Notable as one of the first attempted launches beyond Earth orbit by any country.

American musician Miles Davis released Kind of Blue, which became one of the best-selling and most critically acclaimed jazz recordings of all time.

Quake Lake is formed by the magnitude 7.2 1959 Hebgen Lake earthquake near Hebgen Lake in Montana.

Soviet Union Venera program: Venera 7 launched. It will become the first spacecraft to successfully transmit data from the surface of another planet (Venus).

The Soviet icebreaker Arktika becomes the first surface ship to reach the North Pole.

Double Eagle II becomes first balloon to cross the Atlantic Ocean when it lands in Miserey, France near Paris, 137 hours after leaving Presque Isle, Maine.

The 1985–86 Hormel strike begins in Austin, Minnesota.

The National Assembly of Serbia unanimously adopts new state symbols for Serbia: Bože pravde becomes the new anthem and the coat of arms is adopted for the whole country.

The first forced evacuation of settlers, as part of Israeli disengagement from Gaza, starts.

Michael Phelps won his eighth gold medal of the Summer Olympics in Beijing, setting the record for the most gold medals won by an athlete at a single games.