August 20

Events

AD 14day.year

Agrippa Postumus, maternal grandson of the late Roman emperor Augustus, is mysteriously executed by his guards while in exile.

On August 20, AD 14, Agrippa Postumus, grandson of Emperor Augustus, was mysteriously executed during his exile.
Agrippa Postumus was banished by his grandfather Emperor Augustus on suspicion of treason. Exiled away from Rome, he lived a lonely life cut off from power. On this day, his guards strangled him under secret orders with no public trial. His death was concealed for political reasons, leaving few reliable accounts. Ancient historians speculate that the act was meant to secure the succession for Tiberius. The brutal killing underscores the ruthless nature of Roman imperial politics. Even after two millennia, the motives behind his execution remain a subject of scholarly debate.
AD 14 Agrippa Postumus Roman emperor Augustus
636day.year

Battle of Yarmouk: Arab forces led by Khalid ibn al-Walid take control of the Levant away from the Byzantine Empire, marking the first great wave of Muslim conquests and the rapid advance of Islam outside Arabia.

In 636, Arab forces under Khalid ibn al-Walid secured a decisive victory at the Battle of Yarmouk, wresting control of the Levant from the Byzantine Empire.
The Battle of Yarmouk took place over six days in August 636 near the Golan Heights. Commanded by Khalid ibn al-Walid, the Rashidun cavalry outmaneuvered the Byzantines in a masterful campaign. The defeat shattered Byzantine authority in Syria and advanced the Muslim conquest beyond Arabia. It marked a turning point in early Islamic expansion and opened the Levant to Muslim rule. The victory demonstrated Khalid's tactical genius and boosted the morale of Arab forces. Following the battle, major cities like Damascus fell without significant resistance. Yarmouk remains one of the most celebrated military achievements in Islamic history.
636 Battle of Yarmouk Arab Khalid ibn al-Walid Levant Byzantine Empire Muslim Islam Arabia
917day.year

Battle of Acheloos: Tsar Simeon I of Bulgaria decisively defeats a Byzantine army.

In 917, Tsar Simeon I of Bulgaria delivered a crushing defeat to Byzantine forces at the Battle of Acheloos, asserting Bulgarian dominance in the Balkans.
The Battle of Acheloos occurred on August 20, 917 near the Achelous River (modern Devoll, Albania). Simeon I commanded a well-prepared Bulgarian army that exploited the terrain to ambush the Byzantines. The Byzantine commander Leo Phokas suffered devastating losses, and the empire's northern frontier was left vulnerable. The victory solidified Simeon's reputation as a powerful ruler and expanded Bulgarian influence. It ushered in a golden age for the Bulgarian Empire, marked by cultural and economic growth. Byzantine attempts at counteroffensives sporadically failed to reverse the loss. Acheloos stands as one of the most significant medieval Balkan battles.
917 Battle of Acheloos Simeon I of Bulgaria Byzantine
1083day.year

Canonization of the first King of Hungary, Saint Stephen and his son Saint Emeric celebrated as a National Day in Hungary.

On August 20, 1083, Pope Gregory VII canonized Hungary’s first king, Saint Stephen, and his son Saint Emeric, establishing their feast day as a national celebration.
Pope Gregory VII formally declared Stephen I of Hungary and his son Emeric as saints at a ceremony in the Lateran Basilica. Stephen I, who had secured his kingdom's Christian identity, became a symbol of Hungary's place in Western Christendom. His son Emeric, venerated for his piety, was honored alongside him, reinforcing dynastic holiness. The canonization reinforced the alliance between Hungary and the papacy. In Hungary, August 20 evolved into a national holiday celebrating statehood and faith. Festivities include religious services, parades, and cultural events. Today, Hungarians commemorate the day as St. Stephen's Day, honoring their country's founding legacy.
1083 King of Hungary Saint Stephen Saint Emeric
1191day.year

Richard I of England initiates the Massacre at Ayyadieh, leaving 2,600–3,000 Muslim hostages dead.

In 1191 during the Third Crusade, King Richard I ordered the massacre of thousands of Muslim prisoners at Ayyadieh, a brutal event that shocked contemporaries.
After negotiating with Saladin for the release of Christian captives, Richard the Lionheart agreed to exchange Muslim prisoners. When Saladin delayed the prisoner exchange, Richard ordered the execution of 2,600 to 3,000 Muslim captives at Ayyadieh. The gruesome massacre enraged the Muslim world and hardened attitudes on both sides. Though a tactical move, it tarnished Richard's reputation and complicated further negotiations. Chroniclers recorded the horror of the event, which became a symbol of the Crusades' brutality. The massacre at Ayyadieh remains one of the most infamous episodes of medieval warfare.
1191 Richard I of England Massacre at Ayyadieh
1308day.year

Pope Clement V pardons Jacques de Molay, the last Grand Master of the Knights Templar, absolving him of charges of heresy.

On August 20, 1308, Pope Clement V officially pardoned Jacques de Molay, the last Grand Master of the Knights Templar, of heresy charges.
Under intense pressure from King Philip IV of France, Pope Clement V reexamined the trial of Jacques de Molay and found the evidence of heresy to be inconclusive. The papal bull of pardon attempted to restore de Molay's reputation even as the Templar order faced dissolution. Despite this act of clemency, many knights remained imprisoned or exiled across Europe. The episode highlighted the complex interplay between secular and ecclesiastical power in medieval Christendom. De Molay's later execution in 1314 would transform him into a martyr figure. The pardon remains a key moment in the downfall of the Knights Templar and the shifting allegiances of the era.
1308 Pope Clement V Jacques de Molay Grand Master of the Knights Templar heresy
1391day.year

Konrad von Wallenrode becomes the 24th Grand Master of the Teutonic Order.

In 1391, Konrad von Wallenrode was elected the 24th Grand Master of the Teutonic Order, leading the military and monastic state in Prussia.
Konrad von Wallenrode assumed leadership of the Teutonic Knights, a German crusading order, on August 20, 1391. His election came after internal disputes over policy and strategy in the Baltic region. As Grand Master, Wallenrode pursued aggressive campaigns against Lithuania and sought to strengthen the order's territorial holdings. He reformed the order's administration and emphasized military discipline. Under his rule, the Teutonic state continued to influence trade routes across the Baltic. Wallenrode's leadership shaped the order's role in late medieval Eastern Europe. His tenure foreshadowed future conflicts with neighboring powers.
1391 Konrad von Wallenrode Grand Master of the Teutonic Order
1467day.year

The Second Battle of Olmedo takes places as part of a succession conflict between Henry IV of Castile and his half-brother Alfonso, Prince of Asturias.

On August 20, 1467, forces of King Henry IV of Castile faced off against those of his half-brother Alfonso in the Second Battle of Olmedo during a dynastic conflict.
The battle took place near Olmedo in central Spain as part of a succession dispute within the Trastámara dynasty. Henry IV's loyalists, led by notable nobles, clashed with troops supporting Alfonso, Prince of Asturias. Despite fierce fighting, neither side achieved a decisive victory, and both armies withdrew with heavy losses. The stalemate prolonged political instability and factional tension in Castile. However, Henry IV managed to maintain his throne, though his authority remained challenged thereafter. The encounter exemplified the internal strife that characterized late medieval Spanish politics. The Second Battle of Olmedo underscored the fragility of royal succession in 15th-century Europe.
1467 Second Battle of Olmedo Henry IV of Castile Alfonso, Prince of Asturias
1519day.year

Philosopher and general Wang Yangming defeats Zhu Chenhao, ending the Prince of Ning rebellion against the reign of the Ming dynasty's Zhengde Emperor.

In 1519, the Chinese philosopher-general Wang Yangming crushed the Prince of Ning’s rebellion, ending a significant uprising against the Ming dynasty.
Wang Yangming, renowned for his later philosophical teachings, led imperial forces to confront Zhu Chenhao's rebellion in the Prince of Ning affair. The rebel army had seized Nanjing and declared defiance against the Zhengde Emperor. Demonstrating both military acumen and moral leadership, Wang executed rapid maneuvers that forced the insurgents into disarray. By August 20, his troops secured the final decisive victories, capturing rebel leaders. The swift suppression reaffirmed the authority of the central government. The success bolstered Wang's reputation and influenced his development of the 'unity of knowledge and action' doctrine. The Prince of Ning rebellion thus became a pivotal moment in both his military and intellectual career.
1519 Wang Yangming Zhu Chenhao Prince of Ning rebellion Ming dynasty Zhengde Emperor
1648day.year

The Battle of Lens is the last major military confrontation of the Thirty Years' War, contributing to the signing of the Peace of Westphalia in October that year.

On August 20, 1648, the French army under Louis II de Bourbon, Prince of Condé, won the Battle of Lens, the last major clash of the Thirty Years' War.
The Battle of Lens saw French forces confront a Spanish army near the town of Lens in northern France. Commanded by the Great Condé, the French achieved a decisive victory, inflicting heavy casualties on the Spanish infantry and cavalry. The triumph bolstered French prestige and weakened Habsburg influence in Europe. As the final significant engagement of the Thirty Years' War, Lens paved the way for peace negotiations. The subsequent Peace of Westphalia, signed in October 1648, reshaped the political map of Europe. This battle underscored the rise of France as a dominant continental power. Scholars consider Lens a turning point that accelerated the multi-state equilibrium in 17th-century Europe.
1648 Battle of Lens Thirty Years' War Peace of Westphalia
1672day.year

Former Grand Pensionary Johan de Witt and his brother Cornelis are lynched by a mob in The Hague.

In 1672, Johan de Witt and his brother Cornelis were brutally lynched by a mob in The Hague during a period of political crisis in the Dutch Republic.
On August 20, 1672, Johan de Witt, the Grand Pensionary of Holland, and his brother Cornelis were attacked by an enraged crowd in The Hague. The brothers were accused of treason and blamed for the Republic's military failures during the Rampjaar or 'Year of Disaster'. A mob dragged them from prison, brutally beat them, and murdered them in front of the city hall. The violent act marked a turning point in Dutch politics and fueled further instability within the Republic. Their deaths symbolized the collapse of republican leadership and paved the way for William of Orange's rise to power. The incident remains one of the most shocking episodes of political violence in the Netherlands' history.
1672 Grand Pensionary Johan de Witt Cornelis The Hague
1707day.year

The first Siege of Pensacola comes to an end with the failure of the British to capture Pensacola, Florida.

The first Siege of Pensacola in 1707 ended in defeat for the British, who failed to capture the Spanish-held port in Florida.
During the War of the Spanish Succession, British forces launched a siege on the Spanish fort at Pensacola, Florida. The operation aimed to weaken Spain's control of the Gulf Coast and expand British influence in North America. The British laid siege for several weeks but were hampered by logistical challenges and tough Spanish defenses. Spanish garrison commanders skillfully repelled repeated assaults and maintained supply lines. In August 1707, the British finally abandoned the siege and withdrew, marking a rare setback in their colonial campaigns. The event highlighted the strategic importance of Pensacola and shaped subsequent regional conflicts.
1707 Siege of Pensacola Pensacola, Florida