War is horrible, there is nothing nice about war. Wars cause death and ruin lives. Here are some wars that people have forgotten. All this info is from what was taught in high school, books and websites.
1.) Russo-Japanese War
A war between Japan and Russia, it started in 1904 and ended in 1905. This war was a territorial dispute. Russia outnumbered Japan but Japan still managed to defeat Russia single-handedly. It was a sort of humiliating defeat for the Russians because the Russians viewed Japan as inferior. Tsar Nicholas the second called the Japanese "little yellow monkies", so Japan's victory against Russia silenced him. Many people agree that Imperial Japan's military was in it's prime in those days.
2.) Mongol invasions of Eastern Europe
The Mongol empire is a empire people always forget about. The Mongol empire was a group of nomadic tribes from Northern Asia; the Mongol empire was a very large empire that conquered multiple nations. The invasion started in 1223 and the Mongol reign lasted till 1240. The Mongols took over Russia and made it all the way to Eastern Poland. The Mongols were outnumbered but they still defeated their enemies which included Teutonic Knights, Knights Templar, Polish and Hungarian soldiers.
The Mongols utilized gunpowder as weapons, such as explosives, which gave them a advantage over their European foes. Western Europe wasn't invaded because the Mongol leader Ogedei Khan died from binge drinking, which caused the Mongols to retreat to their homeland. During the mongol occupations of Eastern and parts of Central Europe, many mongol soldiers(all males) had "sexual relations" with the local women. It's because of this that some Eastern and central Europeans look slightly Asian. The Mongols are also credited with introducing gunpowder to Europe.
3.) Mongol invasions of Japan
The Mongols attempted to invade Japan twice but both invasions failed due to the geographical location, climate and military of Japan. The battles took place in Kyushu. The Japanese fought battles amongst themselves prior to the Mongol invasions, so during the first invasions of Japan in 1274, the Japanese were unprepared. The Mongols out numbered the Japanese and used explosives. The Japanese had reinforcements that would have overwhelmed the Mongol invaders but they weren't near the battlefield, so the defenders needed to hold off the Mongols long enough until the Japanese reinforcements arrived. The reinforcements were not needed since there was a massive typhoon that devastated the Mongolian fleet which gave the Japanese a major advantage over the Mongols. The remaining Mongols were no match for the Japanese; the Mongol invasion was repelled by the Japanese.
During the second Mongol invasion of Japan in 1281, the Japanese were more prepared for the Mongol invasions, the Japanese built a defensive wall. After the Samurai repelled the Mongols, another typhoon devastated the Mongol fleet. The Mongols once again failed at invading Japan. These typhoons became known as "Kamikaze"(divine wind). In both invasions the Mongols only made it to some of the coasts of Japan. Strong Japanese resistance repulsed the Mongols. The Mongols were planning a third invasion but they cancelled it because it's said that they believed Japan was protected by a supernatural force.
4.) Spanish Civil War
A war that started in 1936 and ended in 1939; it was between the Spanish Nationalists (fascism) and the Spanish Republicans (various ideologies). The nationalists won that war; the Third Reich supported the Spanish nationalists while the Soviets supported the Spanish Republicans. As a result of the fascist victory, Spain became a fascist country and it stayed fascist until 1975.
5.) Winter War
A war fought between Finland and Russia. The war started in 1939 and it ended in 1940. The winner of this war was Finland, which defeated a larger Soviet army and Finland remained independent. Finland would face the Soviets in the continuation war, and the Finnish would lose some territory to the Soviets but Finland remained independent. Pictured below are the uniforms Finland used during that war.
These are wars that people have unfortunately forgotten about.