38day.year
Drusilla, Caligula's sister who died in June, with whom the emperor is said to have an incestuous relationship, is deified.
Emperor Caligula posthumously deifies his sister Drusilla, elevating her to divine status amid scandalous rumors.
On September 23, 38 AD, Roman Emperor Caligula officially declared his deceased sister Drusilla a goddess.
Drusilla had died in June of that year, and Caligula's deep affection for her fueled persistent rumors of an incestuous bond.
By granting her divine status, he sought to elevate her memory and legitimize his own controversial rule.
The deification was celebrated with public ceremonies and a newly erected temple in her honor.
This act reflected the emperor's increasing autocratic style and helped shape the imperial cult.
Historians view this as a clear example of Caligula's manipulation of religious traditions for political ends.
38
Drusilla
Caligula
1122day.year
Pope Callixtus II and Holy Roman Emperor Henry V agree to the Concordat of Worms to put an end to the Investiture Controversy.
Pope Callixtus II and Emperor Henry V sign the Concordat of Worms, ending the Investiture Controversy.
After decades of conflict over bishop appointments, the Concordat of Worms brought a lasting compromise.
On September 23, 1122, Pope Callixtus II and Holy Roman Emperor Henry V negotiated terms that delineated ecclesiastical and imperial powers.
Bishops would be elected by church authorities with the emperor present at ceremonies, while secular investiture remained under imperial influence.
The agreement ended violent clashes between popes and princes, restoring relative harmony across Christendom.
It set a precedent for Church-State relations in medieval Europe and influenced canon law development.
The settlement underscored the growing power of the papacy and shaped interactions between religious and secular rulers for centuries.
1122
Pope Callixtus II
Henry V
Concordat of Worms
Investiture Controversy
1338day.year
The Battle of Arnemuiden, in which a French force defeats the English, is the first naval battle of the Hundred Years' War and the first naval battle in which gunpowder artillery is used.
French forces win the first naval encounter of the Hundred Years' War at Arnemuiden, introducing gunpowder artillery at sea.
On September 23, 1338, the Battle of Arnemuiden became the first naval engagement of the Hundred Years' War.
A French fleet intercepted an English merchant convoy off the coast of Arnemuiden in modern-day Netherlands.
It marked the earliest recorded use of gunpowder artillery aboard ships, giving the French a crucial firepower advantage.
The engagement foreshadowed a new era of maritime warfare, where cannon and firearms shaped naval tactics.
Although limited in scale, Arnemuiden set the stage for protracted naval conflicts between England and France.
Historians view it as a pivotal moment in the evolution of medieval naval armaments and strategy.
1338
Battle of Arnemuiden
Hundred Years' War
1409day.year
The Battle of Kherlen is the second significant victory over Ming dynasty China by the Mongols since 1368.
Mongol forces achieve a significant victory over the Ming dynasty at the Battle of Kherlen.
On September 23, 1409, Mongol troops secured a decisive win against Ming China at the Battle of Kherlen.
This clash in northeastern Asia was the second major Mongol triumph since their ousting from power in 1368.
Leveraging superior cavalry tactics and intimate knowledge of the steppe terrain, they inflicted heavy casualties on Ming forces.
The battle exposed weaknesses in Ming border defenses and prompted Beijing to strengthen fortifications.
It underscored the enduring threat the Mongol khanates posed to their former empire.
The victory influenced later diplomatic and military engagements between the Mongols and the Ming court.
1409
Battle of Kherlen
1459day.year
The Battle of Blore Heath, the first major battle of the English Wars of the Roses, is won by the Yorkists.
Yorkist troops win the first major battle of the Wars of the Roses at Blore Heath.
On September 23, 1459, the Battle of Blore Heath marked the opening major engagement of the English Wars of the Roses.
Yorkist forces under the Earl of Salisbury ambushed a Lancastrian army near Market Drayton in Staffordshire.
Despite being outnumbered, the Yorkists exploited surprise and advantageous terrain to rout the Lancastrians.
The victory boosted Yorkist morale and intensified the dynastic struggle between the houses of York and Lancaster.
It set a brutal precedent for the civil conflicts that would ravage England for decades.
Blore Heath highlighted fractured noble loyalties and foreshadowed further bloodshed in the contest for the throne.
1459
Battle of Blore Heath
1561day.year
King Philip II of Spain issues cedula, ordering a halt to colonizing efforts in Florida.
King Philip II of Spain issues a royal cedula halting new colonization efforts in Florida.
On September 23, 1561, King Philip II of Spain issued a royal cedula ordering a halt to further colonizing expeditions in Florida.
The decree responded to harsh conditions, resistance from Indigenous communities, and the high costs of remote settlements.
Spanish officials redirected resources toward more profitable colonies in the Caribbean and South America.
The order froze significant European expansion in North America for decades, shaping the region's development.
It illuminated the challenges of sustaining distant outposts in unfamiliar and hostile environments.
Florida remained sparsely settled by Europeans until renewed colonization efforts in the 18th century.
1561
Philip II of Spain
cedula
1642day.year
First English Civil War: The Battle of Powick Bridge, the first engagement between the primary field armies of the Royalists and the Parliamentarians, ended in a Royalist victory.
Royalist cavalry triumphs over Parliamentarian forces in the first combat of the English Civil War at Powick Bridge.
On September 23, 1642, the Battle of Powick Bridge marked the first military engagement of the First English Civil War.
Near Worcester, a Royalist cavalry detachment clashed with and defeated a smaller Parliamentarian advance guard.
Although a skirmish in scale, the fight demonstrated the effectiveness of cavalry in the conflict.
The outcome boosted Royalist confidence and foreshadowed a protracted civil war across England.
It influenced both sides' tactics and underscored the deep political and religious divisions within the kingdom.
Historians regard Powick Bridge as the spark that ignited a broader struggle for the English throne.
1642
First English Civil War
Battle of Powick Bridge
Royalists
Parliamentarians
1779day.year
American Revolution: John Paul Jones, naval commander of the United States, on board the USS Bonhomme Richard, wins the Battle of Flamborough Head.
John Paul Jones wins a dramatic naval victory aboard the USS Bonhomme Richard at Flamborough Head.
On September 23, 1779, during the American Revolutionary War, naval captain John Paul Jones engaged HMS Serapis off the coast of England at the Battle of Flamborough Head.
Despite commanding the battered USS Bonhomme Richard, Jones famously declared, "I have not yet begun to fight!"
His crew boarded the British vessel in intense close-quarters combat, ultimately forcing its surrender after hours of fierce action.
The victory provided a vital morale boost to the revolutionary cause and showcased American naval determination.
It also secured greater support from France and cemented Jones's reputation as a bold maritime commander.
The battle remains one of the most celebrated naval engagements of the Revolution.
1779
American Revolution
John Paul Jones
USS Bonhomme Richard
Battle of Flamborough Head
1803day.year
Second Anglo-Maratha War: The Battle of Assaye is fought between the British East India Company and the Maratha Empire in India.
British East India Company forces under Arthur Wellesley defeat the Maratha Empire at the Battle of Assaye.
On September 23, 1803, the Battle of Assaye saw British East India Company troops clash with the Maratha Empire in western India.
Led by Major General Arthur Wellesley, later the Duke of Wellington, the British executed a bold dawn assault across the Kaitna River.
Despite facing a numerically superior enemy, Wellesley’s forces captured key Maratha artillery positions and routed their army.
The victory significantly strengthened British influence on the subcontinent and boosted Wellesley’s military reputation.
Assaye is often cited as one of Wellesley’s finest battles for its daring tactics and decisive outcome.
The engagement shifted the regional balance of power and paved the way for further British expansion in India.
1803
Second Anglo-Maratha War
Battle of Assaye
British East India Company
Maratha Empire
1821day.year
Tripolitsa, Greece, is captured by Greek rebels during the Greek War of Independence.
Greek revolutionaries capture Tripolitsa, delivering a major blow to Ottoman control.
On September 23, 1821, insurgent forces of the Greek War of Independence seized the fortified city of Tripolitsa from Ottoman rule.
The fall of Tripolitsa in the Peloponnese region effectively broke the Ottoman stronghold in southern Greece.
Following the victory, Greek fighters executed many Ottoman officials and settlers, consolidating revolutionary control.
News of the triumph galvanized European public opinion and increased support for the Greek cause.
The capture marked a turning point in the struggle for independence and the eventual establishment of a Greek state.
Historians view Tripolitsa’s fall as a decisive moment that legitimized and energized the movement for nationhood.
1821
Tripolitsa
1846day.year
Astronomers Urbain Le Verrier, John Couch Adams and Johann Gottfried Galle collaborate on the discovery of Neptune.
In September 1846, mathematicians and astronomers collaborated to pinpoint the position of Neptune, leading to its first observation.
In the mid-19th century, astronomers observed irregularities in Uranus's orbit that hinted at another planet.
Independent calculations by Urbain Le Verrier in France and John Couch Adams in England predicted where to look.
On September 23, 1846, Johann Gottfried Galle at the Berlin Observatory trained the telescope on the predicted region and spotted Neptune.
This marked the first discovery of a planet through mathematical prediction, a triumph of theoretical astronomy.
Neptune's discovery expanded our understanding of the outer Solar System and showcased international scientific cooperation.
1846
Urbain Le Verrier
John Couch Adams
Johann Gottfried Galle
discovery of Neptune
1868day.year
The Grito de Lares occurs in Puerto Rico against Spanish rule.
The Grito de Lares was the first major uprising in Puerto Rico against Spanish colonial rule in 1868.
On September 23, 1868, Puerto Rican rebels launched the Grito de Lares, an armed revolt against Spanish authority.
Led by Ramón Emeterio Betances and Segundo Ruiz Belvis, insurgents sought independence for the island.
Although the rebellion was quickly suppressed by Spanish forces, it became a symbol of Puerto Rican nationalism.
The event inspired future movements for autonomy and cultural identity in Puerto Rico.
Today, the Grito de Lares is commemorated as a key moment in the island's quest for self-determination.
1868
Grito de Lares