On This Day in History: September 6

Across the centuries, September 6 has witnessed defining turning points in world history. From the culmination of the first global circumnavigation to major political shifts and international milestones, this date highlights remarkable chapters of human resilience, discovery, and governance across diverse eras and continents.

394 — Battle of the Frigidus Ends in Roman Imperial Reunion

On September 6, 394, Roman Emperor Theodosius I won a decisive victory against the forces of the usurper Eugenius and Frankish general Arbogast at the Battle of the Frigidus, located along the modern border region of Italy and Slovenia. The defeat of Eugenius reunited the Eastern and Western halves of the Roman Empire under a single ruler for what proved to be the final time in history.

1522 — Juan Sebastián Elcano Completes the First Global Circumnavigation

On September 6, 1522, Spanish navigator Juan Sebastián Elcano steered the ship Victoria into the harbor of Sanlúcar de Barrameda, Spain. Having originally departed under Ferdinand Magellan in 1519, the battered ship and its 18 surviving crew members became the first to successfully sail around the entire globe, fundamentally reshaping European understanding of global geography.

1620 — The Mayflower Departs Plymouth, England

On September 6, 1620, the merchant vessel Mayflower set sail from the port town of Plymouth, England, carrying 102 passengers and roughly 30 crew members. Bound across the North Atlantic, the voyagers—composed of religious Separatists seeking worship free from the Church of England as well as tradespeople—eventually made landfall in North America to establish Plymouth Colony.

1870 — Louisa Ann Swain Casts Landmark Vote in Wyoming

On September 6, 1870, in the town of Laramie, Wyoming Territory, 69-year-old Louisa Ann Swain cast a ballot in a general municipal election. Swain made history as the first woman in the United States to legally vote under a general suffrage law, following the passage of equal voting legislation by the Wyoming territorial legislature in 1869.

1901 — President William McKinley Is Shot at the Pan-American Exposition

On September 6, 1901, United States President William McKinley attended a public greeting inside the Temple of Music at the Pan-American Exposition in Buffalo, New York. In the reception line, anarchist Leon Czolgosz approached the president with a concealed revolver and shot him twice at close range. President McKinley survived the initial attack but succumbed to gangrene and infection eight days later on September 14.

1914 — The First Battle of the Marne Begins in France

On September 6, 1914, during the opening months of World War I, French Commander-in-Chief Joseph Joffre ordered an Allied counter-offensive against the advancing German First and Second Armies near the Marne River east of Paris. The clash halted the rapid German advance into France, prevented the fall of the capital, and led to the establishment of the entrenched Western Front.

1966 — South African Prime Minister Hendrik Verwoerd Is Assassinated

On September 6, 1966, South African Prime Minister Hendrik Verwoerd, a principal architect of the apartheid system of racial segregation, was assassinated inside the House of Assembly chamber in Cape Town. Parliamentary messenger Demetrio Tsafendas approached the prime minister at his desk and fatally stabbed him before being detained by legislators and staff.

1968 — Swaziland Gains Full Independence from the United Kingdom

On September 6, 1968, the southern African nation of Swaziland (now known as Eswatini) gained complete national independence after decades of British colonial administration as a high commission territory and protectorate. King Sobhuza II assumed leadership over the sovereign constitutional monarchy, concluding a diplomatic transition negotiated with the British government.

1991 — Leningrad Renamed Saint Petersburg and Baltic Independence Recognized

On September 6, 1991, during the political transformation of the Soviet Union, the Presidium of the Supreme Soviet of the Russian SFSR formally restored the original historic name of Saint Petersburg to the country's second-largest city, which had been renamed Leningrad in 1924. On the exact same day, the State Council of the Soviet Union officially recognized the complete national independence of the three Baltic states: Estonia, Latvia, and Lithuania.

2007 — Israel Carries Out Operation Orchard in Syria

On September 6, 2007, the Israeli Air Force conducted a classified military strike codenamed Operation Orchard against a facility located in the Deir ez-Zor region of eastern Syria. Intelligence officials later disclosed that the strike targeted and destroyed an undeclared nuclear reactor site being constructed with assistance from North Korea.