Today in History : April 4

• 503 BC – According to the Fasti Triumphales, Roman consul Agrippa Menenius Lanatus celebrated a triumph for a military victory over the Sabines.
• 1147 – First historical record of Moscow.
• 1287 – King Wareru founds Kingdom of Ramannadesa, and proclaims independence from Pagan Empire
• 1581 – Francis Drake is knighted for completing a circumnavigation of the world.
• 1660 – Declaration of Breda by King Charles II of England.
• 1721 – Sir Robert Walpole takes office as the first Prime Minister of the United Kingdom under King George I.
• 1768 – In London, England, Great Britain, Philip Astley stages the first modern circus.
• 1796 – Georges Cuvier delivered his first paleontological lecture at École Centrale du Pantheon of the Muséum national d'histoire naturelle on living and fossil remains of elephants and related species, founding the science of Paleontology.
• 1812 – U.S. President James Madison enacts a ninety-day embargo on trade with the United Kingdom.
• 1814 – Napoleon abdicates for the first time and names his son Napoleon II as Emperor of the French.
• 1818 – The United States Congress adopts the flag of the United States with 13 red and white stripes and one star for each state (then 20).
• 1841 – William Henry Harrison dies of pneumonia becoming the first President of the United States to die in office and with the shortest term served.
• 1850 – The Great Fire of Cottenham, a large part of the Cambridgeshire village (England) is burnt to the ground in suspicious circumstances.
• 1850 – Los Angeles, California is incorporated as a city.
• 1859 – Bryant's Minstrels debut "Dixie" in New York City in the finale of a blackface minstrel show.
• 1865 – American Civil War: A day after Union forces capture Richmond, Virginia, U.S. President Abraham Lincoln visits the Confederate capital.
• 1866 – Alexander II of Russia narrowly escapes an assassination attempt by Dmitry Karakozov in the city of Kiev.
• 1873 – The Kennel Club is founded, the oldest and first official registry of purebred dogs in the world.
• 1887 – Argonia, Kansas elects Susanna M. Salter as the first female mayor in the United States.
• 1905 – In India, an earthquake hits the Kangra Valley, killing 20,000, and destroying most buildings in Kangra, Mcleodganj and Dharamshala
• 1913 – The Greek aviator Emmanouil Argyropoulos becomes the first pilot to die in the Hellenic Air Force when his plane crashes.
• 1930 – The Communist Party of Panama is founded.
• 1933 – U.S. Navy airship, USS Akron, is wrecked off the New Jersey coast due to severe weather.
• 1939 – Faisal II becomes King of Iraq.
• 1944 – World War II: First bombardment of oil refineries in Bucharest by Anglo-American forces kills 3000 civilians.
• 1945 – World War II: American troops liberate Ohrdruf forced labor camp in Germany.
• 1945 – World War II: American troops capture Kassel.
• 1949 – Twelve nations sign the North Atlantic Treaty creating the North Atlantic Treaty Organization.
• 1958 – The CND peace symbol is displayed in public for the first time in London.
• 1960 – France agrees to grant independence to the Mali Federation, a union of Senegal and French Sudan.
• 1964 – The Beatles occupy the top five positions on the Billboard Hot 100 pop chart.
• 1965 – The first model of the new Saab Viggen fighter aircraft is unveiled.
• 1967 – Martin Luther King, Jr. delivers his "Beyond Vietnam: A Time to Break Silence" speech in New York City's Riverside Church.
• 1968 – Martin Luther King, Jr. is assassinated by James Earl Ray at a motel in Memphis, Tennessee. Robert F. Kennedy's speech on the assassination of Martin Luther King, Jr.
• 1968 – Apollo program: NASA launches Apollo 6.
• 1968 – AEK Athens BC becomes the first Greek team to win the European Basketball Cup.
• 1969 – Dr. Denton Cooley implants the first temporary artificial heart.
• 1973 – The World Trade Center in New York is officially dedicated.
• 1973 – A Lockheed C-141 Starlifter, dubbed the Hanoi Taxi, makes the last flight of Operation Homecoming.
• 1975 – Microsoft is founded as a partnership between Bill Gates and Paul Allen in Albuquerque, New Mexico
• 1975 – Vietnam War: Operation Baby Lift – A United States Air Force Lockheed C-5A Galaxy transporting orphans, crashes near Saigon, South Vietnam shortly after takeoff; 172 die.
• 1976 – Prince Norodom Sihanouk resigns as leader of Cambodia and is placed under house arrest.
• 1979 – President Zulfikar Ali Bhutto of Pakistan is executed.
• 1981 – The Islamic Republic of Iran Air Force mounts an attack on H-3 Airbase and destroys about 50 Iraqi aircraft.
• 1983 – Space Shuttle Challenger makes its maiden voyage into space (STS-6).
• 1984 – President Ronald Reagan calls for an international ban on chemical weapons.
• 1988 – Governor Evan Mecham of Arizona is convicted in his impeachment trial and removed from office.
• 1991 – Senator John Heinz of Pennsylvania and six others are killed when a helicopter collides with their airplane over an elementary school in Merion, Pennsylvania.
• 1991 – The current flag of Hong Kong is adopted for post-colonial Hong Kong during the Third Session of the Seventh National People's Congress.
• 1994 – Marc Andreessen and Jim Clark found Netscape Communications Corporation under the name "Mosaic Communications Corporation".
• 1996 – Comet Hyakutake is imaged by the USA Asteroid Orbiter Near Earth Asteroid Rendezvous.
• 2002 – The Angolan government and UNITA rebels sign a peace treaty ending the Angolan Civil War.
• 2007 – Fifteen British Royal Navy personnel held in Iran are released by the Iranian President.
• 2013 – More than 70 people are killed in a building collapse in Thane, India.