On this day in 1989 the peaceful protests in Tiananmen Square in Beijing, China were suppressed by the Chinese army. Over 1 million people showed up to protest the government and its oppression. Right on cue the government sent in tanks. It had started a month and a half earlier when students gathered to create a makeshift memorial to a fallen leader of democratic reforms in China. It slowly gathered momentum until its violent repression. The famous piece of video showing one man standing in front of a tank, refusing to move was seen all over the world. It didn't help, he was never heard from again, as were many of his fellow protesters.
On this day in 1940 the battle of Dunkirk ends, the result of a rousing German victory in mainland Europe. The Germans had forced the entire British army, and a large chunk of the French army into the English Channel. Lucky for them Hitler ordered his troops to halt and wait for reinforcements, allowing British ships to evacuate most of the troops. Live to fight another day.