On this day: 1 July

Tiberius Julius Alexander orders his Roman legions in Alexandria to swear allegiance to Vespasian as Emperor.

Battle of Dorylaeum: Crusaders led by prince Bohemond of Taranto defeat a Seljuk army led by sultan Kilij Arslan I.

The Battle of La Higueruela takes place in Granada, leading to a modest advance of the Kingdom of Castile during the Reconquista.

Spanish conquistadors led by Hernán Cortés fight their way out of Tenochtitlan after nightfall.

Union of Lublin: The Kingdom of Poland and the Grand Duchy of Lithuania confirm a real union; the united country is called the Polish–Lithuanian Commonwealth or the Republic of Both Nations.

War of the Grand Alliance: Marshal de Luxembourg triumphs over an Anglo-Dutch army at the battle of Fleurus.

Lexell's Comet is seen closer to the Earth than any other comet in recorded history, approaching to a distance of 0.0146 astronomical units (2,180,000 km; 1,360,000 mi).

Johann Georg Tralles discovers the Great Comet of 1819 (C/1819 N1). It is the first comet analyzed using polarimetry, by François Arago.

The five Central American nations of Guatemala, El Salvador, Honduras, Nicaragua, and Costa Rica declare independence from the First Mexican Empire after being annexed the year prior.

Belgium introduced its first series of postage stamps, known as epaulettes (example pictured).

Signing of the Quinault Treaty: The Quinault and the Quileute cede their land to the United States.

American Civil War: Confederate general Robert E. Lee launched a series of disjointed and ultimately unsuccessful assaults on the nearly impregnable Union position on Malvern Hill in Henrico County, Virginia.

The Russian State Library is founded as the Library of the Moscow Public Museum.

American Civil War: The Battle of Gettysburg begins.

Slavery is abolished in the Dutch colony of Surinam, a date subsequently celebrated as Ketikoti in independent Suriname.

The United States Department of Justice formally comes into existence.

The Remington No. 1, the first commercially successful typewriter, went on sale.

Canada joins the Universal Postal Union.

Charles Taze Russell publishes the first edition of the religious magazine The Watchtower.

The world's first international telephone call is made between St. Stephen, New Brunswick, Canada, and Calais, Maine, United States.

The Congo Free State is established by King Leopold II of Belgium.

The United States terminates reciprocity and fishery agreement with Canada.

Spanish–American War: The Battle of San Juan Hill is fought in Santiago de Cuba, Cuba.

The French government enacts its anti-clerical legislation Law of Association prohibiting the formation of new monastic orders without governmental approval.

Start of first Tour de France bicycle race.

SOS is adopted as the international distress signal.

Germany dispatches the gunboat SMS Panther to Morocco, sparking the Agadir Crisis.

World War I: Leutnant Kurt Wintgens of the then-named German Deutsches Heer's Fliegertruppe army air service achieves the first known aerial victory with a synchronized machine-gun armed fighter plane, the Fokker M.5K/MG Eindecker.

World War I: Russia launches the "Kerensky offensive" against Austria-Hungary to capture Galicia, its final offensive of the war.

Chinese General Zhang Xun seizes control of Beijing and restores the monarchy, installing Puyi, last emperor of the Qing dynasty, to the throne. The restoration is reversed just shy of two weeks later, when Republican troops regain control of the capital.

The Chinese Communist Party is founded by Chen Duxiu and Li Dazhao, with the help of the Far Eastern Bureau of the Russian Social Democratic Labour Party (Bolsheviks), who seized power in Russia after the 1917 October Revolution, and the Far Eastern Secretariat of the Communist International.

Yan Ruisheng (advertisement pictured), the first full-length Chinese film, is released in Shanghai.

Seven of the sixteen American railroad labor organizations staged a nationwide strike (striking workers pictured) that lasted two months.

The Parliament of Canada suspends all Chinese immigration.

The Singapore Improvement Trust was founded to oversee the construction of public housing in Singapore, where more than three quarters of residents live.

United Airlines begins service (as Boeing Air Transport).

Wiley Post and Harold Gatty become the first people to circumnavigate the globe in a single-engined monoplane aircraft (a Lockheed Vega).

Australia's national broadcaster, the Australian Broadcasting Corporation, is formed.

The first Grant Park Music Festival was held in Chicago's Grant Park.

In Regina, Saskatchewan, police and Royal Canadian Mounted Police ambush strikers participating in the On-to-Ottawa Trek.

Second World War: The Grand Quartier Général of the French Army was disbanded, following the French surrender.

World War II: start of the First Battle of El Alamein.

The Australian Federal Government becomes the sole collector of income tax in Australia as State Income Tax is abolished.

The City of Tokyo and the Prefecture of Tokyo are both replaced by the Tokyo Metropolis.

Crossroads Able is the first postwar nuclear weapon test.

The Philippine Air Force is established.

The first flight departed New York City's John F. Kennedy International Airport, then known as New York International Airport.

Muhammad Ali Jinnah (Quaid-i-Azam) inaugurates Pakistan's central bank, the State Bank of Pakistan.

The merger of two princely states of India, Cochin and Travancore, into the state of Thiru-Kochi (later re-organized as Kerala) in the Indian Union ends more than 1,000 years of princely rule by the Cochin royal family.

The International Geophysical Year begins.

The Canadian Broadcasting Corporation links television broadcasting across Canada via microwave.

Flooding of Canada's Saint Lawrence Seaway begins.

B. Anthony Stewart is credited with the first image on the cover of National Geographic featuring the 49-star flag of the United States after Alaska's admission to the Union as a U.S. state.

Ghana became a republic, with Kwame Nkrumah as its first president.

Independence of Rwanda and Burundi.

ZIP codes are introduced for United States mail.

The first color television transmission in Canada takes place from Toronto.

The People's Liberation Army Rocket Force (first known as the 2nd Artillery Corps) is founded.

Merger Treaty: The European Community is formally created out of a merger between the Common Market, the European Coal and Steel Community, and the European Atomic Energy Commission.

The United States Central Intelligence Agency's Phoenix Program is officially established.

Formal separation of the United Auto Workers from the AFL–CIO in the United States.

Portugal grants autonomy to Madeira.

The Northern Territory in Australia is granted self-government.

Sony introduced the Walkman, a portable audio player that changed listening habits by offering users the ability to play one's own choice of music.

"O Canada" officially becomes the national anthem of Canada.

The Ministry of State Security is established as China's principal intelligence agency

The PG-13 rating is introduced by the MPAA.

The American radio station WFAN in New York City is launched as the world's first all-sports radio station.

German reunification: East Germany accepts the Deutsche Mark as its currency, thus uniting the economies of East and West Germany.

Cold War: The Warsaw Pact is officially dissolved at a meeting in Prague.

The Finnish operator Radiolinja is launched as the world's first GSM network.

Space Shuttle program: Space Shuttle Columbia is launched on STS-94, a re-flight of the prematurely-ended STS-83 mission with the same crew.

Over 500,000 people protest against efforts to pass anti-sedition legislation in Hong Kong.

Saturn orbit insertion of Cassini–Huygens begins at 01:12 UTC and ends at 02:48 UTC.

The Qinghai–Tibet railway first operates in China.

Croatia becomes the 28th member of the European Union.

The United States–Mexico–Canada Agreement replaces NAFTA.

At the centennial ceremony of the Dominion of Newfoundland National War Memorial, the Commonwealth War Graves Commission allows an unprecedented second Canadian Tomb of the Unknown Soldier. The Royal Newfoundland Regiment soldier is entombed in the memorial at this ceremony.