May 01
Overview
Holidays & Observances
Christianfeast day:
Aldebrandus, Amator, Andeolus, Aredius of Gap, Asaph, Augustin Schoeffler,Jean-Louis Bonnard(part ofVietnamese Martyrs), Benedict of Szkalka, Bertha of Val d'Or, Brioc, James the Less(Anglican Communion), Jeremiah, Joseph the Worker(Roman Catholic), Julian of Bale, BlessedKlymentiy Sheptytsky(Ukrainian Greek Catholic Church), Mafalda of Portugal, Marcouf, Orientius, Peregrine Laziosi, Philip the Apostle(Anglican Communion,Lutheran Church), Richard Pampuri, Seven Apostolic MenCaecilius of ElviraCtesiphon of VergiumEuphrasius of IlliturgisHesychius of CazorlaIndaletiusSecundus of AbulaTorquatus of Acci, Sigismund of Burgundy, Theodard, Ultan, May 1 (Eastern Orthodox liturgics)
A collective feast day honoring numerous Christian saints observed on May 1 across various denominations.
Armed Forces Day(Mauritania)
A national holiday in Mauritania celebrating the country's military forces and their service.
Constitution Day(Argentina,Latvia,Marshall Islands)
Celebrations marking the promulgation or adoption of national constitutions in Argentina, Latvia, and the Marshall Islands.
Commemoration of the states ofMaharashtraandGujaratfollowing the foundation ofSamyukta Maharashtra Samiti(India):
Maharashtra Day
Maharashtra Day celebrates the formation of the state of Maharashtra in India, observed annually on May 1.
International Sunflower Guerrilla Gardening Day
An international observance encouraging community-led guerrilla gardening projects featuring sunflowers.
Lei Day(Hawaii)
Hawaii's annual celebration of the lei, a traditional garland symbolizing love, friendship, and honor.
International Workers' DayorLabour Day(International), and its related observances:
Law Day (United States), formerly intended to counterbalance the celebration ofLabour Day. (United States), Loyalty Day, formerly intended to counterbalance the celebration ofLabour Day. (United States)
An international observance of labor rights known as International Workers' Day, with related U.S. observances Law Day and Loyalty Day.
May Day(beginning of Summer) observances in the Northern hemisphere(seeApril 30):
Calan Mai(Wales), Beltane(Gaelic)
Traditional Celtic festivals marking the beginning of summer, observed as Calan Mai in Wales and Beltane in Gaelic cultures.
Aldebrandus
Feast day commemorating Saint Aldebrandus, venerated for his pastoral service and devotion.
Events
Diocletian and Maximian retire from the office of Roman emperor.
On May 1, 305, Emperors Diocletian and Maximian unexpectedly abdicated, marking the first voluntary surrender of imperial power in Rome.
The Nea Ekklesia is inaugurated in Constantinople, setting the model for all later cross-in-square Orthodox churches.
In 880, the grand Nea Ekklesia in Constantinople was consecrated, introducing the cross-in-square design that shaped Orthodox church architecture.
Norman mercenaries land at Bannow Bay in Leinster, marking the beginning of the Norman invasion of Ireland.
On May 1, 1169, Norman mercenaries landed at Bannow Bay, launching the Norman invasion of Ireland that reshaped its medieval history.
Wars of Scottish Independence end: By the Treaty of Edinburgh–Northampton, England recognises Scotland as an independent state.
The 1328 Treaty of Edinburgh–Northampton formally ended the Wars of Scottish Independence as England recognised Scotland's sovereignty.
Christopher Columbus presents his plans discovering a western route to the Indies to the Spanish Queen Isabella I of Castile.
In 1486, Christopher Columbus formally presented his ambitious proposal for a westward route to Asia to Queen Isabella I of Castile.
Henry Morgan's raid on Lake Maracaibo, the Spanish Armada de Barlovento is defeated by an English Privateer fleet led by Captain Henry Morgan.
On May 1, 1669, Captain Henry Morgan led English privateers to defeat the Spanish Armada de Barlovento in a daring raid on Lake Maracaibo.
The Act of Union joining England and Scotland to form the Kingdom of Great Britain takes effect.
The Acts of Union 1707 officially united England and Scotland into a single sovereign state, the Kingdom of Great Britain.
Publication of Species Plantarum by Linnaeus, and the formal start date of plant taxonomy adopted by the International Code of Botanical Nomenclature.
In 1753, Carl Linnaeus published Species Plantarum, introducing the binomial nomenclature system that underpins modern plant taxonomy.
The Slave Trade Act 1807 takes effect, abolishing the slave trade within the British Empire.
On May 1, 1807, the British Parliament enacted the Slave Trade Act, ending the transatlantic slave trade in the British Empire.
Births
John I
A 13th-century noble who served as Count of Hainaut and shaped regional alliances in medieval Europe.
The first Habsburg King of Germany who reigned from 1273 to 1291 and laid the groundwork for his dynasty's future power.
Edmund FitzAlan
A 14th-century English noble and statesman who served as the 9th Earl of Arundel and navigated the turbulent reign of Edward II.
Rinchinbal Khan
Child emperor of the Yuan dynasty whose brief 1332 reign highlighted court intrigue and the challenges of dynastic succession.
Sidonie of Bavaria
A Bavarian princess notable as the eldest daughter of Duke Albrecht IV of Bavaria-Munich and member of the Wittelsbach dynasty.
Johannes Stadius
A Renaissance astronomer and mathematician known for his influential tables of planetary positions and contributions to early modern astronomy.
Franciscus Junius
A Reformation-era theologian who made significant contributions to Protestant biblical scholarship and church teaching.
Wolphert Gerretse
A Dutch settler and pioneering colonist who helped establish the New Netherland colony in early 17th-century North America.
Marco da Gagliano
An innovative Italian composer whose works bridged late Renaissance madrigal style and the emerging Baroque era.
Deaths
Arcadius
Byzantine emperor who succeeded his father Theodosius I and ruled the Eastern Roman Empire amid court intrigues.
Marcouf
Frankish missionary and hermit venerated as Saint Marcouf for his preaching and charitable works.
Wang Zongji
Chinese prince who claimed the imperial title during the upheaval following the Tang dynasty's collapse.
Scottish princess who became Queen of England as the wife of King Henry I and a patron of religious institutions.
Diarmait Mac Murchada
King of Leinster whose appeal to Norman knights led to the beginning of the Anglo-Norman invasion of Ireland.
Roger de Moulins
Grand Master of the Knights Hospitaller who led the order's military and charitable activities during the Crusades.
Walter de Gray
Archbishop of York and Lord Chancellor who shaped ecclesiastical and royal policy in 13th-century England.
King of Serbia who consolidated his realm and promoted economic and cultural development in the 13th century.
Prince of Achaea whose rule in the Peloponnese balanced military campaigns with diplomatic alliances.