Years of the Shōgun: Japan’s Medieval Era

The new Hulu series Shōgun, based on James Clavell’s novel, opens a new window, is a tale set in a time of tumult and violence. The story of the first English sailor to reach Japan and the daimyo (feudal lord) who takes him into his service is set in 1600 AD, at the end of Japan’s medieval period. This was a time when ancient traditions faced rapid technological change, and many clans fought for the seat of political power. Japan’s culture and its distinct political structures, arts, and ways of warfare had developed over its centuries-long medieval era. Learn all about the history of medieval Japan with this article, and, when you’re done, check out more historical fiction about Japan:

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The Shōgun’s Rise and the Samurai Class

Japan’s medieval era is generally believed to have begun in 1185 AD, when the Kamakura period, opens a new window began. Two things defined the Kamakura period; the Shōgunate gaining de facto political control over Japan, and the emergence of the samurai class, wealthy landowners who fought in feudal conflicts. Originally the shōgun was a supreme commander, opens a new window who was appointed by the Emperor to lead his armies, but did not actually have political control himself. This changed when Minamoto no Yoritomo, opens a new window seized leadership of the Minamoto clan and set up headquarters in Kamakura, opens a new window. From 1180 to 1185, he fought the rival Taira clan, opens a new window, which had considerable power in the Imperial Court, and his rival relatives Minatomo no Yuukie, opens a new window and Minamoto no Yoshinaka, opens a new window

Yoritomo’s breakthrough came in the Battle of Dannoura, opens a new window in April 1185. This naval battle saw the Minamoto clan outnumbered by the Taira, who had lost most of their territory but still had the support of the Imperial government. The Taira had Emperor Antoku, who was about six years old, with them to bolster their morale. They also knew the area better than the Minamoto did and used the tide to their advantage in battle. But they had a brutal surprise awaiting them. The son of one of their generals, Taguchi Shigeyoshi, was being held captive by the Minamoto, but the Taira still believed him to be loyal. In reality, he had actually defected, opens a new window to the Minamoto, and told them exactly which ship the Emperor was on. The Minamoto withstood the attack of the Taira, and Shigeyoshi’s squadron attacked the Emperor’s ship from the rear. Once it was clear they had lost, most of the Taira nobles committed suicide; Emperor Antoku’s grandmother drowned herself while holding him. 

The Minamoto's victory brought much political power to the office of the Shōgun. Although the Emperor and his court remained in Kyoto, most decisions were now made in the military capital of Kamakura. With the rise of a military government came the samurai, opens a new window class as the Shōgun’s chosen warriors. Yoritomo’s government gave him the exclusive power to grant men the title of “samurai,” giving them the power to enforce laws and keep the peace on the estates of wealthy nobles. With few restrictions on their power, the samurai were able to take over land and political control, opens a new window from the non-warrior nobles they once served. 

As the Kamakura era progressed, the samurai class developed a very distinct set of cultural traditions. The religious beliefs of the samurai class were heavily influenced by Zen Buddhism, opens a new window. Zen Buddhism’s focus on an individual’s courage and mental strength and its use of meditation and koan, opens a new window to clear the mind and reach a higher mental state gave it special appeal to an elite warrior class. From the study of Zen Buddhism came bushido, the samurai code of ethics and behavior. Bushido roughly translates, opens a new window as “way of the warrior” and stressed fearlessness in battle and courage in life as the highest moral virtues. Devotion, opens a new window to one’s lord was above all other duties, and, if this honor was not upheld or the samurai failed on the battlefield, he would have to commit seppuku, opens a new window (ritual suicide). The act of taking one’s own life with a blade was viewed as such a brave act that it embodied the bushido spirit and allowed the dying samurai to regain his honor. 

From Honor and Blood: The Samurai During the Mongol Invasions

What made the samurai legendary figures were their actions during the Mongol invasions. The first Mongol invasion occurred in 1274, opens a new window, after several years of Kublai Khan, opens a new window--the first emperor of the Mongol-led Yuan dynasty of China--attempting to make the Emperor of Japan pay him tribute. The Mongol fleet set out from Masan in the south of the Korean peninsula and made landfall on November 5, 1274, at Tsushima, opens a new window. The invasion force conquered the island within a week and went on to take Iki, opens a new window, the next island in the chain. But the governor of Iki was better prepared than Tsushima’s and sent one of his trusted samurai, Sozaburo, to warn the Japanese mainland before Iki fell. 

The Mongols reached Hakata Bay, opens a new window on November 19 and sent their 3,000 troops in to do battle with a Japanese defense force roughly the same size. The samurai found the Mongols difficult to fight; the Mongols' tight formation stymied the samurai's swords, and the Mongols had access to Chinese gunpowder and explosives. The samurai fought bravely but could not stop the Mongols from establishing a beachhead at the end of the day. The Mongols decided to go back to their ships, as their commanders were worried about being killed in night raids by the Japanese. But once the Mongols returned to their ships, a powerful typhoon smashed into their fleet, sinking many of the ships and killing thousands of men. The invasion force was broken and returned to Korea, lacking the manpower to retake Hakata Bay. Japan had been saved by a miracle of weather they called the kamikaze, opens a new window (divine wind). 

The peace the kamikaze granted Japan was short lived. Kublai conquered the remaining Southern Song territories of China in 1279, established the Yuan dynasty,, opens a new window and created an invasion force several times the size of the 1274 fleet. Kublai’s invasion force was so large that it was divided into an Eastern Fleet and a Southern Fleet that would act in a coordinated assault. The Eastern Fleet started its attack on June 9 and quickly took Tsushima and Iki once more. They were supposed to wait for the arrival of the larger Southern Fleet before beginning their attack on the mainland, but the Eastern Fleet commanders disobeyed orders and split their force to attack Hakata Bay and Nagato, opens a new window quickly. They found both ports well protected, with a new stone wall in Hakata, sharp spikes lining both beaches, and boat raids by samurai trying to burn their ships. 

The Japanese were able to hold off the Mongols until the Southern Fleet arrived in August. The battle to take Hakata became a stalemate, with neither the Japanese nor the Mongols able to seize the upper hand. The mainland was still well defended by the stone wall, and the samurai were lethal with their yumi, opens a new window bows, which could be fired from horseback as well as from the walls. It was the yumi that made the samurai deadly warriors, with the majority of their kills coming from the bow. Even with their precise archery, the Japanese could not repel the combined Mongol forces, which numbered over 140,000 men, opens a new window. But on August 15, Japan was saved once more by another kamikaze, which sank much of the Mongol fleet and left the survivors stranded and unable to fight. The Japanese killed them by the thousands, utterly defeating the Mongols and ensuring Kublai and his Yuan heirs would never attempt another invasion. 

Roots of Tradition: Culture in Medieval Japan

After the second Mongol invasion, Japan’s culture was free to evolve in relative isolation, shaped by the choices of the Shōgunate and limited influence from the rest of East Asia. The Shōgunate and samurai class favored a different style of art than the Imperial Court did. Japan’s military government and warriors favored art that tended towards realistic descriptions and depictions of settings, giving it a sense of immediacy and energy. Art was heavily influenced by the growing popularity of Pure Land Buddhism, opens a new window in Japan. Pure Land Buddhism was popular among non-samurai warriors for granting them a path to escape their violent existence through faith in Amitābha, opens a new window and gave art focus and meaning by representing the emotions and movement of life. 

The importance of the samurai in Japan’s culture also influenced the development of Japan’s national sport. Sumo wrestling predated Japan’s medieval period; early matches were fought at the request of the Emperor as far back as 23 BC, opens a new window. This early form of sumo had few rules and was very dangerous, often fought to the death of one of the wrestlers. Organized sumo tournaments and a system of rules emerged during the medieval period, and the sport’s focus changed from representing a battle of the gods to a means of training samurai. The objective of the match changed from breaking an opponent’s body to pushing them out of the dohyo (ring area) or toppling them off their feet. Daimyos (feudal lords) sponsored an increasing number of tournaments as the medieval era progressed. Oda Nobunaga, opens a new window, a particularly powerful daimyo who lived at the very end of Japan’s medieval period, hosted massive tournaments every year in his castle, and created the shape of the modern dohyo. In the Edo period (1600-1868) following Japan’s medieval era, sumo became a professional sport with a ranking system and regular tournament schedules, and remains very popular in Japan today.

Medieval Japan also had a rich theatrical tradition represented in the development of Noh theatre. Noh was codified, opens a new window in its oldest tradition, the Komparu School, during the Nanboku-Cho period (1336-1392). Noh is a very stylized theatrical format, in which movement is conveyed through dance, the main character’s actor wears a mask representing their heightened emotions, and a chorus on both sides of the stage speaks to add emotional resonance to each scene. Because Noh relied entirely, opens a new window on scripted movements and dialogue, with no room for improvisation, hundreds of Noh plays were preserved and can be performed today just as they were centuries ago. The shōgun Ashikaga Yoshimitsu, opens a new window particularly loved Noh, and performances of it were the favored entertainment at his court. Noh would remain a cultural fixture of Japan long after his reign, and Noh plays are performed today in all of Japan’s major cities.  

Age of Chaos: The Sengoku Period

The last phase of Japan’s medieval era was the Sengoku Jidai (Warring States Period). Lasting roughly from the middle of the 15th century to the early 17th century, this was an extremely violent and chaotic period in Japan’s history, when the Shōgunate lost much of its authority and daimyos from powerful families fought each other for control of the country. The Ōnin War, opens a new window is often cited as the beginning of the Sengoku Period. Shōgun Ashikaga Yoshimasa, opens a new window had first named his brother, Ashikaga Yoshimi, as heir, but then had a son, Yoshihisa. His son's and brother’s claims were backed by two opposing samurai families who both wanted to puppetize the Ashikaga Shōgunate. The Ōnin War began in 1467, opens a new window and ended in 1477 and was an extremely chaotic conflict, with the two factions switching which claimant they backed as the war proceeded. The deaths of the two samurai who began the war in 1473, Yamana Sozen and Hosokawa Katsumoto, did not end the fighting, and neither did Yoshihisa being formally named Shōgun in 1474. The conflict finally ended in 1477 when the remaining Yamana forces left Kyoto, leaving behind a burned and ruined city. Yoshihisa officially ruled as Shōgun but was effectively a puppet of the Hosokawa forces.

Although Kyoto was stabilized, the violence had already spread far beyond the city into the Japanese countryside. All across the country, daimyos fought each other with increasingly large standing armies, and the Shōgunate did little to stop the fighting. When Portuguese merchants first arrived in Japan in 1543, opens a new window after their ship was blown off course, they found a nation willing to pay well for powerful weapons. The Portuguese changed the face of Japanese warfare with the introduction of the arquebus, opens a new window. Though this matchlock rifle was heavy and slow to reload, it was lethal against even the most well armored of Japanese troops. Samurai quickly began commanding armies of ashigaru, opens a new window (foot soldiers) armed with arquebus instead of the traditional long pike. The Portuguese also brought with them the first Catholic missionaries, opens a new window to Japan. They enjoyed early success, converting the daimyo Omura Sumitada, opens a new window, who opened Nagasaki to the Jesuits.

The 3 Great Unifiers and Modern Japan’s Dawn 

The Sengoku Era would finally end as a result of the actions of the three Great Unifiers of Japan: Oda Nobunaga, Toyotomi Hideyoshi, and Tokugawa Ieyasu. Nobunaga’s rise began in 1560,, opens a new window when he defeated the much larger army of his rival, Imagawa Yoshimoto, at the Battle of Okehazama. His military success came from his ingenuity, opens a new window and forward thinking, as he was the first daimyo to make use of infantry armed with the arquebus. Nobunaga attempted to unify the country first by backing Ashikaga Yoshiyaki’s, opens a new window claims to the Shōgunate, but Yoshiyaki turned on him; after Nobunaga defeated his forces in 1573, he abolished the Ashikaga Shōgunate. Nobunaga’s fellow daimyos, Tokugawa Ieysau and Toyotomi Hideyoshim proved to be much more loyal and valuable allies as he consolidated his power. But before he could unify the entire country, Nobunaga was assassinated, opens a new window on June 21, 1582, by his vassal Akechi Mitsuhide. The exact motive remains unknown.  

After Nobunaga’s assassination, Toyotomi Hideyoshi, opens a new window became the most powerful of his former retainers and continued the work of unifying Japan. He began his ascent by avenging Nobunaga and destroying Akechi Mitsuhide’s forces at the Battle of Yamazaki, opens a new window. There were disagreements and battles among Nobunaga’s former retainers as to who should be the successor of the Oda clan. Hideyoshi fought Tokugawa Ieyasu, who was backing a different Oda clan member, to a stalemate at the Battle of Komaki and Nagakute, opens a new window. The two men were impressed with each other’s power and became allies, further improving Hideyoshi’s position. To consolidate his hold on power, Hideyoshi used “sword hunts, opens a new window” to confiscate weapons from anyone not of the samurai class and ordered a thorough nationwide census to estimate population and land fertility for the purpose of setting tax rates. He also banished, opens a new window Christian missionaries from Japan to further control the population of Kyushu; this was a sharp break from Nobunaga, who sometimes backed the Jesuits because of his struggles against Buddhist warrior-monks.   

When Hideyoshi died in 1598, another power struggle occurred between backers of his son and Tokugawa Ieyasu, opens a new window, Nobunaga’s last retainer. Ieyasu benefitted from his cautious and calculating nature; because he did not commit to Hideyoshi’s doomed Korea campaigns, opens a new window like some of the other daimyos, his military forces had fewer losses and were in better shape to fight. Instead, Ieyasu defeated the Hōjō, opens a new window daimyo and gained control of land that made him wealthier and more powerful than any other military leader in Japan. When it came time for the battle of succession, Ieyasu fought the backers of the Toyotomi clan at the Battle of Sekigahara, opens a new window. On October 20, 1600, in a mountainous valley with an army of 89,000 soldiers, Tokugawa Ieyasu defeated the armies loyal to Toyotomi’s son and won the last great battle of the Sengoku era. His strength now unrivaled, the Emperor formally pronounced him Shōgun in 1603, marking the end of Japan’s medieval period and the beginning of the Tokugawa period, opens a new window, over 260 years of prosperity and stability in Japan.       

Tokugawa Ieyasu’s rise to power was dramatized in many sources, including James Clavell’s Shōgun, opens a new window. This book, a tale of war, love, and political intrigue that tells the tale of Lord Toranaga (a fictionalized version of Ieyasu) can be found in CRRL’s collection. After finishing it, why not read the rest of the books in Clavell’s Asian Saga, opens a new window? Go on a trip back through history with our great books and fill out your summer reading list, opens a new window