On July 17, 1917, during the third year of World War I, Britain’s King George V orders the British royal family to dispense with the use of German titles and surnames, changing the surname of his own family, the decidedly Germanic Saxe-Coburg-Gotha, to Windsor.

On July 17, 1936, the Spanish Civil War begins as a revolt by right-wing Spanish military officers in Spanish Morocco and spreads to mainland Spain. From the Canary Islands, General Francisco Franco broadcasts a message calling for all army officers to join the uprising and overthrow Spain’s leftist Republican government. Within three days, the rebels captured Morocco, much of northern Spain, and several key cities in the south. The Republicans succeeded in putting down the uprising in other areas, including Madrid, Spain’s capital. The Republicans and the Nationalists, as the rebels were called, then proceeded to secure their respective territories by executing thousands of suspected political opponents. Meanwhile, Franco flew to Morocco and prepared to bring the Army of Africa over to the mainland.

An ammunition ship explodes while being loaded in Port Chicago, California, killing 320 people on July 17, 1944. The United States’ World War II military campaign in the Pacific was in full swing at the time. Poor procedures and lack of training led to the disaster.

The final “Big Three” meeting between the United States, the Soviet Union and Great Britain takes place towards the end of World War II, to discuss how geopolitics would shake out after the war. The decisions reached at the Potsdam Conference ostensibly settled many of the pressing issues between the three wartime allies, but the meeting was also marked by growing suspicion and tension between the United States and the Soviet Union.

As part of a mission aimed at developing space rescue capability, the U.S. spacecraft Apollo 18 and the Soviet spacecraft Soyuz 19 rendezvous and dock in space. As the hatch was opened between the two vessels, commanders Thomas P. Stafford and Aleksei Leonov shook hands and exchanged gifts in celebration of the first such meeting between the two Cold War adversaries in space. Back on Earth, United Nations Secretary General Kurt Waldheim congratulated the two superpowers for the Apollo-Soyuz Test Project and praised their unprecedented spirit of cooperation and peace in planning and executing the mission.

Shortly after takeoff from New York’s Kennedy International Airport, a TWA Boeing 747 jetliner bound for Paris explodes over the Atlantic Ocean, killing all 230 people aboard. Flight 800 had just received clearance to initiate a climb to cruise altitude when it exploded without warning. Because the plane was loaded with fuel for the long transatlantic journey, it vaporized within moments, creating a fireball seen almost all along the coastline of Long Island.