August 25

Emperor Constantine V humiliates nineteen high-ranking officials, after discovering a plot against him. He executes the leaders, Constantine Podopagouros and his brother Strategios.

Emperor Constantine V uncovered a conspiracy and publicly humiliated nineteen top officials. He executed the ringleaders, Constantine Podopagouros and his brother Strategios, solidifying his hold on power.

The Dutch city of Ommen receives city rights and fortification rights from Otto III, the Archbishop of Utrecht.

In 1248, Otto III, the Archbishop of Utrecht, granted city and fortification rights to Ommen. This recognition marked Ommen's rise as a fortified urban center in medieval Netherlands.

Regent George Mouzalon and his brothers are killed during a coup headed by the aristocratic faction under Michael VIII Palaiologos, paving the way for its leader to ultimately usurp the throne of the Empire of Nicaea.

In 1258, regent George Mouzalon and his brothers were assassinated in a noble-led coup. This bloody conspiracy led by Michael VIII Palaiologos opened the path for his eventual rule.

Philip III, although suffering from dysentery, becomes King of France following the death of his father Louis IX, during the Eighth Crusade. His uncle, Charles I of Naples, is forced to begin peace negotiations with Muhammad I al-Mustansir, Hafsid Sultan of Tunis.

In 1270, during the Eighth Crusade, Philip III succeeded his father Louis IX as King of France despite suffering from dysentery. His ascension accelerated peace negotiations in Tunis between his uncle Charles I of Naples and Sultan Muhammad I al-Mustansir.

The Honourable Artillery Company, the oldest surviving regiment in the British Army, and the second most senior, is formed.

In 1537, the Honourable Artillery Company was founded as part of London's militia, becoming the oldest surviving regiment in the British Army. It remains the second most senior unit in British military history.

António Mota and a few companions become the first Europeans to visit Japan.

In 1543, Portuguese merchant António Mota and his companions became the first Europeans to land in Japan. Their arrival heralded the beginning of trade and cultural exchanges between Europe and Japan.

War of the Portuguese Succession: Spanish victory at the Battle of Alcântara brings about the Iberian Union.

In 1580, Spanish troops won the Battle of Alcântara against Portuguese forces, triggering the union of Spain and Portugal under Philip II. The Iberian crowns remained united for six decades.

Galileo Galilei demonstrates his first telescope to Venetian lawmakers.

In 1609, Galileo Galilei presented his first telescope to Venetian lawmakers, impressing them with distant observations. His demonstration marked a breakthrough in the study of the heavens.

Portuguese forces are defeated by the Kingdom of Kandy at the Battle of Randeniwela in Sri Lanka.

In 1630, the Sinhalese kingdom of Kandy routed Portuguese troops at Randeniwela in Sri Lanka. The victory preserved Kandy's sovereignty against European colonization.