History Events on May 20

Shakespeare's sonnets are first published in London, perhaps illicitly, by the publisher Thomas Thorpe.
#Shakespeare's_sonnets

The independence of East Timor is recognized by Portugal, formally ending 23 years of Indonesian rule and three years of provisional UN administration (Portugal itself is the former colonizer of East Timor until 1976).
#East_Timor

In the Chuknagar massacre, Pakistani forces massacre thousands, mostly Bengali Hindus.
#Chuknagar_massacre

Yangzhou massacre: The ten day massacre of 800,000 residents of the city of Yangzhou, part of the Transition from Ming to Qing.
#Yangzhou_massacre

Generalissimo Chiang Kai-shek wins the 1948 Republic of China presidential election and is sworn in as the first President of the Republic of China at Nanjing.
#Chiang_Kai-shek

First publications of the discovery of the HIV virus that causes AIDS in the journal Science by Luc Montagnier.
#HIV

The Popular Movement of the Revolution political party is established in the Democratic Republic of the Congo.
#Popular_Movement_of_the_Revolution

Empress Ariadne marries Anastasius I. The widowed Augusta is able to choose her successor for the Byzantine throne, after Zeno (late emperor) dies of dysentery.
#Ariadne_(empress)

Treaty of Jeddah: The United Kingdom recognizes the sovereignty of King Ibn Saud in the Kingdoms of Hejaz and Nejd, which later merge to become the Kingdom of Saudi Arabia.
#Treaty_of_Jeddah_(1927)

Krakatoa begins to erupt; the volcano explodes three months later, killing more than 36,000 people.
#Krakatoa

Civil rights: The Supreme Court of the United States rules in Romer v. Evans against a law that would have prevented any city, town or county in the state of Colorado from taking any legislative, executive, or judicial action to protect the rights of gays and lesbians.
#LGBT_rights_in_the_United_States

American Civil War: The state of Kentucky proclaims its neutrality, which will last until September 3 when Confederate forces enter the state. Meanwhile, the State of North Carolina secedes from the Union.
#American_Civil_War

The First Council of Nicaea is formally opened, starting the first ecumenical council of the Christian Church.
#First_Council_of_Nicaea

Amelia Earhart takes off from Newfoundland to begin the world's first solo nonstop flight across the Atlantic Ocean by a female pilot, landing in Ireland the next day.
#Amelia_Earhart

World War II: Battle of Crete: German paratroops invade Crete.
#Battle_of_Crete

History of cinema: The first public display of Thomas Edison's prototype kinetoscope.
#History_of_film

John Cabot sets sail from Bristol, England, on his ship Matthew looking for a route to the west (other documents give a May 2 date).
#John_Cabot

The Triple Alliance between the German Empire, Austria-Hungary and the Kingdom of Italy is formed.
#Triple_Alliance_(1882)

The International System of Units (SI): The base units are redefined, and the International Prototype Kilogram becomes obsolete.
#International_System_of_Units

In Operation Redwing, the first United States airborne hydrogen bomb is dropped over Bikini Atoll in the Pacific Ocean.
#Operation_Redwing

The Battle of Hamburger Hill in Vietnam ends.
#Battle_of_Hamburger_Hill

Cuba gains independence from the United States. Tomás Estrada Palma becomes the country's first President.
#Cuba

In a referendum in Quebec, the population rejects, by 60% of the vote, a government proposal to move towards independence from Canada.
#1980_Quebec_referendum

The Mecklenburg Declaration of Independence is allegedly signed in Charlotte, North Carolina.
#Mecklenburg_Declaration_of_Independence

The Battle of Dun Nechtain is fought between a Pictish army under King Bridei III and the invading Northumbrians under King Ecgfrith, who are decisively defeated.
#Battle_of_Dun_Nechtain

In the United States, the Armed Forces Security Agency, the predecessor to the National Security Agency, is established.
#National_Security_Agency

The Holocaust: The first prisoners arrive at a new concentration camp at Auschwitz.
#The_Holocaust

U.S. President Abraham Lincoln signs the Homestead Act into law, opening 84 million acres of public land to settlers.
#Abraham_Lincoln

By the Law of 20 May 1802, Napoleon Bonaparte reinstates slavery in the French colonies, revoking its abolition in the French Revolution.
#Law_of_20_May_1802

At least 27 people are killed and 50 others injured when a 6.0-magnitude earthquake strikes northern Italy.
#2012_Northern_Italy_earthquakes
York Minster is badly damaged by fire.
#York_Minster

Signing of the Metre Convention by 17 nations leading to the establishment of the International System of Units.
#Metre_Convention

Portuguese explorer Vasco da Gama discovers the sea route to India when he arrives at Kozhikode (previously known as Calicut), India.
#Vasco_da_Gama
The Chinese authorities declare martial law in the face of pro-democracy demonstrations, setting the scene for the Tiananmen Square massacre.
#Democracy

Levi Strauss and Jacob Davis receive a U.S. patent for blue jeans with copper rivets.
#Levi_Strauss

Ignatius of Loyola is seriously wounded in the Battle of Pampeluna.
#Ignatius_of_Loyola

While visiting the royal Mercian court at Sutton Walls with a view to marrying princess Ælfthryth, King Æthelberht II of East Anglia is taken captive and beheaded.
#Mercia

Cartographer Abraham Ortelius issues Theatrum Orbis Terrarum, the first modern atlas.
#Cartography

American Civil War: Battle of Ware Bottom Church: In the Virginia Bermuda Hundred campaign, 10,000 troops fight in this Confederate victory.
#Battle_of_Ware_Bottom_Church

King Sancho IV of Castile creates the Estudio de Escuelas de Generales in Alcalá de Henares.
#Sancho_IV_of_Castile

The city of Magdeburg in Germany is seized by forces of the Holy Roman Empire and most of its inhabitants massacred, in one of the bloodiest incidents of the Thirty Years' War.
#Magdeburg