In the 12th Century Japan, around 1180, the Genpei War was a rather brutal affair with two factions of the same family the aristocratic clan, the Kyoto-based Taira and the country-based Minamoto clan. The Minamoto clan wanted to give the samurai the right to own land. For three hundred years the samurai has been fighting for the Emperor but have not been allowed to own land. The Taira had a puppet Emperor on the throne that they controlled.
Tomoe Gozen was born in the same home as Lord Kiso no Yoshinaka (or Minamoto no Yoshinaka). Her father was a samurai and her mother was a wet nurse. Back then women trained to fight defensively in order to protect the home. Tomoe was such a good fighter that she was allowed to train offensively as well.
The three rules of the samurai are to serve, to slaughter, and to die well. She was trained to use a bow and arrow and a naginata, a polearm with a curved blade at the end. She became an expert in both. It is not clear whether she was Yoshinaka's concubine or his wife, but he was so impressed with her skill that he made her his leading commander (ippo no taisho).
She excelled during battles against the Taira including the Battle of Yogotagawara in 1181 where she collected the heads of seven of the enemies. Or the Battle of Tonimiyama where she led 1,000 men to victory in 1183. In 1184 she led 300 against a mighty 6,000 and was one of five to survive. Tomoe and Yoshinaka are the ones to take Kyoto where the Emperor and nobles fled. The last battle in 1184 of Awazu, was against Minamoto no Yoritomo Yoshinaka's cousin who was battling him for control of the country. There were five of them left in the battle and Yoshinaka tells Tomoe to leave the field of battle but she first seeks out the best Tiara samurai and takes his head just to show her honor and loyalty. Yoshinaka was fatally wounded in the battle and asked Tomoe to leave him to die alone. Some say because he did not want to die in front of a woman and lose honor.
At the battle of Dan no ura the Tiara would be thoroughly defeated and with the months ahead they would be hunted down and killed. In 1192 Minamoto Yoritomo would be declared the first shogun of Japan which would last for the next seven hundred years. The Genpei Wars are represented in Japan's flag with the red representing the Taira and the white representing the Minamoto. Many movies have been made about this war and it is highly celebrated.
What happened to Tomoe? No one really knows for sure. Some say she became the concubine of one of Yoritomo's henchmen and gave birth to strongman Asahina Saburo Yoshide. Some say she became a Buddhist nun. Others that she became a peasant hiding from Yoritomo. It is also said that she got revenge by killing Yoshinaka's attackers and taking his head so no one could defile it and walk into the sea. I believe that she lived on as he asked her to which is why we know this story in the first place.
The Heike Monogatari was written some time after the Genpei Wars ended. This is considered a great epic poem in Japan like the Iliad is to Greece. In it, Tomoe is mentioned. In Helen McCullough's The Tale of the Heike she describes Tomoe is in this way from the text:
Tomoe was especially beautiful, with white skin, long hair, and charming features. She was also a remarkably strong archer, and as a swordswoman she was a warrior worth a thousand, ready to confront a demon or god, mounted or on foot. She handled unbroken horses with superb skill; she rode unscathed down perilous descents. Whenever a battle was imminent, Yoshinaka sent her out as his first captain, equipped with strong armor, an oversized sword, and a mighty bow; and she performed more deeds of valor than any of his other warriors.Tomoe was an incredible woman not just for her time, but at any time. She exemplifies the qualities of loyalty, honor, and bravery that we all aspire to have.