All of this info is from documentaries, books and websites.
1.) Temujin/Genghis Khan
A Mongolian conqueror that conquered various nations. He was born in Mongolia in 1162, nobody knows how he looked but he was born in one of the Mongolian tribes. It's said that he was married when he was 16 years old and that he had many wives. He had so many children that many people today are genetically related to him.
He United all of the Mongolian tribes. Many neo-Nazis like to claim Genghis Khan was European without evidence. Historic records and DNA evidence from Genghis Khan's descendants disprove the nonsense that the Neo-Nazis say. Historic records and DNA evidence indicate/prove that Genghis was either Mongolian or Eurasian(Half Mongolian, half Caucasian).After his death, Genghis Khan's successors would continue to expand the Mongol empire.
2.) Atilla the Hun
A leader of the Huns; he is known for his military attacks against the Roman Empire. A lot of people tend to confuse Atilla and the Huns with Genghis and the Mongols, they were two different people. The Huns were of unknown origin although a lot of historians believe that they are related to the Mongols. Atilla attacked Europe before the Mongols did, and Attila's forces took over parts of Central Asia and parts of Europe. After Attila took over Germany, he tried to take over France and Italy but he was fought off by the Western Roman Empire and it's allies.
Nobody knows how he looked but certain sources say that he was either a Eurasian or Turkic. He is said to have had a short height, a broad chest, a large head, a flat nose, small eyes, a thin grey beard and tanned skin. Attila planned to continue attacking the Romans but he drank so much that he died of internal bleeding. Without Attila, the Hunnic empire collapsed.
3.) Oda Nobunaga
A Japanese Daimyo(Japanese warlord) who is credited with almost uniting Japan. For a large chunk of Japan's history, Japan was divided by different clans that were fighting each other. In the Sengoku era of Japan, a Daimyo named Oda Nobunaga would lead his Samurai to score victories against other clans. He nearly united Japan but he would be betrayed by one of his Generals named Akechi Mitsuhide. His General would launch a successful coup d'état on Nobunaga. Nobunaga didn't expect a attack since he was in his territory, so Nobunaga only had a few men guarding him.
His General launched a attack on Nobunaga's position with a large number of samurai. Nobunaga's few guards were defeated. It's not known how Nobunaga died but it's said that Nobunaga committed ritualized suicide (seppuku) in 1582 at the age of 47 which prevented his possible capture. Other sources say he went down swinging. Nobunaga's successor named Toyotomi Hideyoshi would defeat the treacherous general soon after his coup in a battle which resulted in the treacherous general's death. Toyotomi would be the one to unite Japan.
4.) Miyamoto Musashi
A very famous undefeated Japanese swordsman that trained in martial arts when he was young. When he was 13 years old, he killed his first opponent by beating him to death. He defeated various other swordsmen throughout his life. Miyamoto also wrote a book called "the Book of 5 rings" Miyamoto is known for duel wielding swords. Miyamoto died of natural causes in 1645 when he was 60 years old.
Not much is known about him but what is known is that he was a black man who was a servant of an Italian Jesuit, and he accompanied the Jesuit to Japan in 1579. The Europeans gave Yasuke to Nobunaga as a gift. He would become one of Nobunaga's Samurai, since the Japanese in those days had never seen a black person, Nobunaga asked Yasuke to scrub his skin because he thought Yasuke was painted in black ink. After Nobunaga died, he participated in a battle but his side lost so Yasuke surrendered to the other Samurai.
The Samurai felt sorry for him so they didn't kill him; instead, they took him to a temple of Jesuits. Nothing else is known about him. Some people believe he continued to live in Japan others believe he went to Europe. Yasuke wasn't his original name, his original name isn't known. Yasuke is said to have been 6'2" in height. It's also said that Blacks didn't face discrimination in Japan, the Japanese had respect for them.
6.) Frederick the Great
A Prussian/German King that is revered in Germany. He improved the Prussian army, scored many military victories and triumphed over odds in the "seven years war". It's said that he composed the Hohenfriedberger march. The song fridericus Rex was Composed for him. He died in 1786 at the age of 74.
7.) Kuroki Tamemoto
An Imperial Japanese army General that participated in the Russo-Japanese war, a war that Japan won. Kuroki participated in three major battles in which he managed to defeat the Russians. He died in 1923 at the age of 73.
8.) Carl Gustaf Emil Mannerheim
A German-Finnish military leader that fought in the Russo-Japanese War, WWI, Finnish Civil War and the Winter war. He gained fame during the Winter War when he became commander in chief of the Finnish armed forces. After the Winter War, he became the President of Finland. He passed away in 1951 at the age of 83 in Switzerland. He is buried at Helsinki Finland.
9.) Shizuya Hayashi
A Japanese-American soldier that served in the 100th infantry battalion of the U.S. Army during WWII. He was awarded the Distinguished Service Cross because he was able to take over German position even though he was outnumbered. His Distinguished Service Cross was upgraded to the Medal of Honor in 2000. It's believed that the reason why he didn't get the Medal of Honor during WWII was because Asian-Americans faced discrimination during WWII, which is what prevented him from getting the Medal of Honor. So in 2000 he was awarded the Medal of Honor. He passed away in 2008 at the age of 90.
10.) Dieter Dengler
A U.S. Soldier that fought in the Vietnam war, he was captured by the Pathet Lao soldiers after his plane was shot down. He suffered mistreatment and torture and eventually the Pathet Lao handed him over to the Vietnamese. Dieter would escape from the POW camp and he evaded Vietnamese soldiers until he was rescued by U.S. Soldiers. Sadly, he committed suicide in 2001 in front of a fire station, he was 62 years old and he is buried in Arlington cementary. A movie about him was made called "rescue dawn" where he is portrayed by Christian Bale.
11.) Herbert Norman Schwarzkopf
A U.S. Army General that participated in the Vietnam war, the invasion of Grenada and the Persian Gulf war. He is known for leading Operation desert storm in which the US army and the coalition forces liberated Kuwait and defeated the Iraqi army. Herbert passed away in 2012, he is buried in New York.
These are some famous military leaders and soldiers that not many people know about.