August 20
Overview
Holidays & Observances
Christianfeast day:
Amadour, Bernard of Clairvaux, BlessedGeorg Häfner, Heliodorus of Bet Zabdai, Maria De Mattias, Oswine of Deira, Philibert of Jumièges, Samuel(prophet), WilliamandCatherine Booth(Church of England), August 20 (Eastern Orthodox liturgics)
Christian feast day commemorating a diverse group of saints and religious figures, observed in Catholic, Anglican, and Orthodox traditions.
Feast of Asmá’(Baháʼí Faith, only ifBaháʼí Naw-Rúzfalls on March 21)
Baháʼí observance celebrating the Feast of Asmá’, observed when the Baháʼí Naw-Rúz coincides with March 21.
Indian Akshay Urja Day(India)
An annual Indian observance promoting awareness and use of renewable energy resources across the country.
Independence Restoration Day (Estonia), re-declaration of the independence of Estonia from the Soviet Union in 1991.
National holiday in Estonia commemorating the restoration of independence from the Soviet Union in 1991.
Meitei Language Day, also known asManipuri Language Day, the day on whichMeitei(Manipuri) was included in thescheduled languages' listand made one of theofficial languages of India.
Celebration of Meitei (Manipuri) language gaining status as a scheduled and official language of India.
Revolution of the King and the People(Morocco)
National holiday in Morocco marking the 1953 uprising against colonial authorities and the solidarity between the monarchy and citizens.
Saint Stephen's Day (Hungary)
Hungarian national holiday celebrating Saint Stephen I, the first king of Hungary and the foundation of the Hungarian state.
World Mosquito Day
International observance raising awareness about mosquitoes as vectors of deadly diseases and the importance of disease prevention.
Amadour
Feast day of Saint Amadour, the legendary hermit associated with the shrine of Rocamadour in France.
Events
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.
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.
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.
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.
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.
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.
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.
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.
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.
Births
Shahrukh Mirza
Timurid prince who ruled Persia and Transoxiana in the early 15th century.
Antoine Perrenot de Granvelle
French cardinal and statesman, renowned for his extensive art collection.
Jacopo Peri
Italian composer and singer, regarded as a pioneer of early opera.
Thomas Corneille
French dramatist and scholar, younger brother of Pierre Corneille.
Louis Bourdaloue
French Jesuit preacher celebrated for his eloquent sermons at the court of Louis XIV.
Henry Every
Notorious English pirate who plundered ships in the Atlantic and Indian Oceans.
Thomas Simpson
English mathematician and educator, known for developing Simpson’s rule in integration.
Christian Mayer
Czech-born astronomer and teacher, known for pioneering observations of binary stars.
Bernard de Bury
French composer and harpsichordist, prominent at the court of Louis XV.
Deaths
Agrippa Postumus
Agrippa Postumus was the youngest grandson of Emperor Augustus and was adopted as heir. He was later exiled and died under mysterious circumstances.
Mochta
Mochta was an early Irish missionary and saint, a disciple of Saint Patrick who founded the monastery at Louth.
Oswine was King of Deira, remembered for his piety and tragic death during dynastic conflict.
Eadberht was King of Northumbria who later abdicated in favor of monastic life, credited with consolidating his kingdom.
Constantine Lips
Constantine Lips was a Byzantine naval commander and admiral involved in early 10th-century court intrigues.
Pope John XIV led the Catholic Church from 983 until his demise following a Roman revolt against imperial influence.
Bernard of Clairvaux
Bernard of Clairvaux was a leading Cistercian abbot and influential theologian who shaped medieval spirituality.
Rögnvald Kali Kolsson (born 1100)
Rögnvald Kali Kolsson was the Earl of Orkney, revered as a saint and poet who journeyed to Jerusalem.
William Fraser
William Fraser was Bishop of St Andrews and served as Guardian of Scotland during the Wars of Independence.