On September 9

Elizabeth II (pictured) became the longest-reigning monarch of the United Kingdom, surpassing Queen Victoria.

A natural-gas pipeline in San Bruno, California, exploded and "shot a fireball more than 1,000 feet (300 m) in the air", killing eight people.

Two al-Qaeda attackers assassinated Ahmad Shah Massoud, a pivotal Afghan resistance leader, two days before the September 11 attacks in the United States.

The first banknotes of the Portrait Series of the Singapore dollar were introduced by the Board of Commissioners of Currency.

Imagine, the second solo album by John Lennon (pictured), was released.

Allegheny Airlines Flight 853 collided in mid-air with a Piper PA-28 Cherokee flown by a student pilot near Fairland, Indiana, killing all 83 occupants of and destroying both aircraft.

French president Charles de Gaulle delivered his "speech to the German youth" to 20,000 people in the courtyard of Ludwigsburg Palace (pictured).

U.S. president Dwight D. Eisenhower signed the Civil Rights Act of 1957, the first civil rights bill since Reconstruction.

A magnitude-6.7 earthquake struck near Chlef, killing over 1,200 people and forcing the Algerian government to implement comprehensive reforms in building codes.

World War II: About 3,000 Polish Army troops began a nearly month-long defence of the Hel Peninsula during the German invasion of Poland.

At the Lick Observatory in California, Edward Emerson Barnard discovered Amalthea (pictured), a moon of Jupiter and the last natural satellite to be discovered by visual observation.

French Revolutionary Wars: A naval engagement between French and British fleets off the coast of Sumatra ended inconclusively.

The commissioners overseeing the construction of the United States' new capital city named it Washington, D.C., in honor of the first president.

The Stono Rebellion, at the time the largest slave rebellion in the Thirteen Colonies of British America, erupted near Charleston, South Carolina.

Ottoman–Venetian War: After a 40-day siege, the Cypriot city of Nicosia fell to the Ottomans, leading to a massacre of more than 20,000 citizens.

Ottoman wars in Europe: A large Croatian army intercepted Ottoman forces returning to the Sanjak of Bosnia, but was defeated.

Byzantine forces defeated Achaean troops at the Battle of Saint George, taking control of the Arcadia region of Greece.

Yelü Dashi, the Liao general who founded the Qara Khitai, defeated Seljuq and Kara-Khanid forces at the Battle of Qatwan, near Samarkand in present-day Uzbekistan.

After disposing of all relatives who possibly held a claim to the throne, Constantine II, Constantius II and Constans became Roman co-emperors.

Germanic Wars: An alliance of Germanic tribes led by Arminius engaged Roman forces at the Battle of the Teutoburg Forest, defeating three legions within a few days.