The universal sign of surrender has been a white flag for hundreds of years. But do you know the history of where the white flag originated from? It's actually much, much older than you might suppose.
The first known record of a white flag being used to signal surrender was from Livy, a Roman historian. He wrote about a Carthaginian ship that displayed "white wool and branches of olive" as a signal of defeat in the Second Punic War. The historian Tacitus also wrote that white flags were displayed at the Second Battle of Cremona in 69 A.D, when the Vitellians surrendered.
The historical consensus is that white flags became ubiquitous because it was so easy to identify, even in the chaos of warfare. White cloth was also very easy to come by. Surprisingly, white flags were also used as signals of capitulation in ancient China during the Eastern Han dynasty. The habit developed independently of the white flag's use in the West. The flag has a different connotation in the East, where the color white is commonly associated with death.
The color white has been used in battle other than just in flags, too. In Medieval warfare, heralds used to carry white-colored standards and wands to be more easily distinguished from soldiers. Prisoners of War (though they did not bear that official title at the time) were decorated with the color white, usually by placing a piece of white paper in their helmet. Troops who had surrendered and been granted safe passage were ordered to carry white batons as well.
The use of white flags continued to spread throughout Europe in the coming centuries. In the 1550's, the Portugese historian Gaspar Correia wrote that the Zamorin of Calicut, an Indian prince, had peace negotiators carry "white cloth tied to a stick" as a "sign of peace" in 1502. The white flag also made it into Hugo Grotius's De jure belli ac pacis, an extremely influential text about international law, in 1625. He described it as "a tacit sign of demanding a parley, and shall be as obligatory, as if expressed by words."
The white flag was written into the Geneva Conventions in the 19th century as the official international symbol of surrender. According to the Geneva Conventions, it is illegal to feign surrender with a white flag.
The white flag is still the international standard, and is used both in combat situations and in popular culture.