7 March 1974

The Kepler space telescope (depicted), designed to discover Earth-like planets orbiting other stars, was launched.

Dissident Irish republican campaign: Two off-duty British Army soldiers were shot dead by Real IRA paramilitaries outside Massereene Barracks in Antrim, Northern Ireland.

Vietnam War: The United States and South Vietnam began Operation Truong Cong Dinh to sweep the area surrounding the Mekong Delta town of Mỹ Tho to root out Viet Cong forces in the area.

Unarmed civil rights activists marching from Selma to Montgomery, Alabama, were attacked by police (pictured) on "Bloody Sunday".

World War II: At the beginning of the Battle of Remagen, Allied forces unexpectedly captured the Ludendorff Bridge, which possibly hastened the war's conclusion.

The German submarine U-47, one of the most successful U-boats of World War II, disappeared with 45 men on board.

Nazi German forces re-occupied the demilitarized Rhineland, violating both the Treaty of Versailles and the Locarno Treaties that were signed after World War I.

José Paranhos, Viscount of Rio Branco, began a four-year premiership as Prime Minister of the Empire of Brazil, the longest in the state's history.

United States senator Daniel Webster (pictured) delivered a speech advocating compromise on slavery, which proved to be unpopular with abolitionists in his home state.

War of the Sixth Coalition: Napoleon's army forced Mikhail Semyonovich Vorontsov's Russian troops to withdraw from the Chemin des Dames, but French casualties exceeded Russian losses.

A peace treaty brought the Ottoman–Venetian War to an end, ceding Cyprus from the Republic of Venice to the Ottoman Empire.

Emperor Constantine I decreed that Sunday, the day honoring the sun god Sol Invictus (disc pictured), would be the Roman day of rest.

Sweden officially joins NATO, becoming its 32nd member.

Massereene Barracks shooting: The Real Irish Republican Army kills two British soldiers and injures two other soldiers and two civilians at Massereene Barracks, the first British military deaths in Northern Ireland since the end of The Troubles.

Reform of the House of Lords: The British House of Commons votes to make the upper chamber, the House of Lords, 100% elected.

Garuda Indonesia Flight 200 crashes at Adisutjipto International Airport in the Special Region of Yogyakarta, Indonesia, killing 21 people.

The terrorist organisation Lashkar-e-Taiba coordinates a series of bombings in Varanasi, India.

Iran and the United Kingdom break diplomatic relations after a fight over Salman Rushdie and his controversial novel, The Satanic Verses.

Challenger Disaster: Divers from the USS Preserver locate the crew cabin of Challenger on the ocean floor.

Sheikh Mujibur Rahman, political leader of then East Pakistan (present day-Bangladesh), delivers his historic 7th March speech in the Racecourse Field (Now Suhrawardy Udyan) in Dhaka.

Bloody Sunday: A group of 600 civil rights marchers are brutally attacked by state and local police in Selma, Alabama.

Aeroflot Flight 542 crashes in the Yermakovsky District, killing all 31 aboard.

Northwest Orient Airlines Flight 307 crashes in Lynnhurst, Minneapolis, killing 15 people.

Korean War: Operation Ripper: United Nations troops led by General Matthew Ridgway begin an assault against Chinese forces.