Explore 2624 historical events from 0–9.
Japanese patent law is based on the first-to-file principle and is mainly given force by the Patent Act of Japan. Article 2 defines an invention as "the highly advanced creation o…
Invention Day (Japan)
The Days of Military Honour are special memorable dates in the Russian Armed Forces dedicated to the most outstanding victories won by Russia. Some of these dates are state holiday…
Victory over the Teutonic Knights in the Battle of the Ice (Russia; Julian Calendar)
The International Amateur Radio Union (IARU) is an international confederation of national organisations that allows a forum for common matters of concern to amateur radio operator…
World Amateur Radio Day
Ælfheah, more commonly known today as Alphege, was an Anglo-Saxon Bishop of Winchester, later Archbishop of Canterbury from 1006 to 1012. He became an anchorite before being electe…
Christian feast day: Ælfheah of Canterbury (Anglican, Catholic, Orthodox)
Conrad of Ascoli was an Italian Friar Minor and missionary; his feast day is April 19.
Christian feast day: Conrad of Ascoli
Emma of Lesum or Emma of Stiepel was a countess popularly venerated as a saint for her good works. She was married to Liudger of Saxony. She is also the first female inhabitant of …
Christian feast day: Emma of Lesum
Expeditus, also known as Expedite, was said to have been a Roman centurion in Armenia who was martyred around April 303 in what is now Turkey, for converting to Christianity. Consi…
Christian feast day: Expeditus
Saint George the Confessor, also known as Saint George of Antioch, was the Bishop of Antioch in Pisidia in the 8th century. He is venerated as a saint in the Eastern Orthodox Churc…
Christian feast day: George of Antioch
Olof Persson, sometimes Petersson, better known under the Latin form of his name, Olaus Petri, was a clergyman, writer, judge, and major contributor to the Protestant Reformation i…
Christian feast day: Olaus and Laurentius Petri (Lutheran)
Pope Leo IX was the head of the Catholic Church and ruler of the Papal States from 12 February 1049 to his death in 1054. Leo IX is considered to be one of the most historically si…
Christian feast day: Pope Leo IX
Ursmar of Lobbes was a missionary bishop in the Meuse and Ardennes region in present-day Belgium, Germany, Luxemburg and France. He was also the first abbot of Lobbes Abbey.
Christian feast day: Ursmar
April 18 - Eastern Orthodox liturgical calendar - April 20
Christian feast day: April 19 (Eastern Orthodox liturgics)
Bicycle Day is an unofficial celebration on April 19 of the psychedelic revolution and the first psychedelic trip on LSD by Albert Hofmann in 1943, in tandem with his bicycle ride …
Bicycle Day, a psychedelic holiday
Agnes of Montepulciano, OP was a Dominican prioress in medieval Tuscany who was known as a miracle worker during her lifetime. She is honored as a saint by the Catholic Church.
Christian feast day: Agnes of Montepulciano
Pope Anicetus was the bishop of Rome from c. 157 to his death in April 168. According to the Annuario Pontificio, the start of his papacy may have been 153. Anicetus actively oppos…
Christian feast day: Pope Anicetus
Beatification is a recognition accorded by the Catholic Church of a deceased person's entrance into Heaven and capacity to intercede on behalf of individuals who pray in their name…
Christian feast day: Blessed Anastazy Jakub Pankiewicz
Saint Beuno, sometimes anglicized as Bono, was a 7th-century Welsh abbot, confessor, and saint. Baring-Gould gives St Beuno's date of death as 21 April 640, making that date his tr…
Christian feast day: Beuno
Beatification is a recognition accorded by the Catholic Church of a deceased person's entrance into Heaven and capacity to intercede on behalf of individuals who pray in their name…
Christian feast day: Blessed James Bell and John Finch
Marcellinus of Gaul also known as Marcellin was the first bishop of Embrun from 354 AD. He was a native of Africa Proconsularis.
Christian feast day: Marcellinus of Gaul
Beatification is a recognition accorded by the Catholic Church of a deceased person's entrance into Heaven and capacity to intercede on behalf of individuals who pray in their name…
Christian feast day: Blessed Muiris Mac Ionrachtaigh
Theotimus was a writer and friend of St. John Chrysostom. He was bishop of the Scythian diocese of Tomi, near the Black Sea, from 392 to 403, who tried to convert the Huns. He publ…
Christian feast day: Theotimos
April 19 - Eastern Orthodox liturgical calendar - April 21
Christian feast day: April 20 (Eastern Orthodox liturgics)
420 is cannabis culture slang for cannabis consumption, especially smoking around the time 4:20 p.m., and annual cannabis-oriented celebrations held on 4/20, the U.S. notation for …
420 (cannabis culture)
Johannes Bugenhagen, also called Doctor Pomeranus by Martin Luther, was a German theologian and Lutheran priest who introduced the Protestant Reformation in the Duchy of Pomerania …
Christian feast day: Johannes Bugenhagen (Lutheran)