Origins of the Samurai:
The samurai, a class of highly skilled warriors, gradually developed in Japan after the Taika reforms of 646 CE. The reforms included land redistribution and heavy new taxes, meant to support an elaborate Chinese-style empire. As a result, many small farmers had to sell their land and work as tenant farmers.
Meanwhile, a few large landholders amassed power and wealth, creating a feudal system similar to medieval Europe's. As in Europe, the new feudal lords needed warriors to defend their riches. Thus, the samurai warrior (or "bushi") was born.
Early Feudal Era Samurai:
Some samurai were relatives of the landowners, while others were simply hired swords. The samurai code emphasized loyalty to one's master, even over family loyalty. History shows that the most loyal samurai were usually family members or financial dependents of their lords.
In the 900s, the weak emperors of the Heian Era (794-1185) lost control of rural Japan. The country was riven by revolt; the emperor soon wielded power only within the capital. Across the country, the warrior class moved in to fill the power vacuum. By 1100, the samurai effectively held both military and political power over much of Japan.
Rise of Samurai Rule:
The weak imperial line received a fatal blow to its power in 1156, when Emperor Toba died without a clear successor. His sons, Sutoku and Go-Shirakawa, fought for control in a civil war called the Hogen Rebellion (1156). In the end, both would-be emperors lost; the imperial office lost all its remaining power.
During this civil war, the Minamoto and Taira samurai clans rose to prominence. They fought one another in the Heiji Rebellion (1160). After their victory, the Taira established the first samurai-led government. The defeated Minamoto were banished from the capital at Kyoto.
The two clans fought once more in the Genpei War (1180-1185), which ended in victory for the Minamoto. Minamoto no Yoritomo established the Kamakura Shogunate, with the emperor as a mere figurehead. The Minamoto clan ruled much of Japan until 1333. While the Kamakura were powerful, they never conquered the far northern and western areas of the country. The shoguns also faced periodic resistance from other samurai clans.
In 1268, an external threat appeared. Kublai Khan, the Mongol ruler of Yuan China, demanded tribute from Japan. Kyoto refused. The Mongols invaded in 1274 with 600 ships, but a typhoon destroyed their armada. A second invasion fleet in 1281 met the same fate.
Early Muromachi (Ashikaga) Period:
Despite such incredible help from nature, the Mongol attacks cost the Kamakura dearly. Unable to offer land or riches to the samurai leaders who rallied to Japan's defense, the weakened shogun faced a challenge from Emperor Go-Daigo in 1318. The emperor was exiled in 1331, but returned and overthrew the Shogunate in 1333.
This Kemmu Restoration of imperial power lasted only three years. In 1336, the Ashikaga Shogunate under Ashikaga Takauji reasserted samurai rule, but it was weaker than the Kamakura had been. Regional constables called "daimyo" developed considerable power, meddling in the shogunate's succession.
Later Muromachi Period:
By 1460, the daimyo were ignoring orders from the shogun, and backing different successors to the imperial throne. When the shogun, Ashikaga Yoshimasa, resigned in 1464, a dispute between backers of his younger brother and his son ignited even more intense bickering among the daimyo.
In 1467, this squabbling erupted into the decade-long Onin War. Thousands died, and Kyoto was burned to the ground.
The Onin War led directly to Japan's "Warring States Period," or Sengoku. Between 1467 and 1573, various daimyo led their clans in a fight for national dominance. Nearly all of the provinces were engulfed in the fighting.
Restoration of Order:
The Warring States Period began to draw to a close in 1568, when the warlord Oda Nobunaga defeated three other powerful daimyo, marched into Kyoto, and had his favorite, Yoshiaki, installed as shogun.
Nobunaga spent the next 14 years subduing other rival daimyo, and quelling rebellions by fractious Buddhist monks. His grand Azuchi Castle, constructed between 1576 and 1579, became of symbol of Japanese reunification.
In 1582, Nobunaga was assassinated by one of his generals, Akechi Mitsuhide. Hideyoshi, another general, finished the unification and ruled as kampaku (regent). Hideyoshi invaded Korea in 1592 and 1597.
Tokugawa Shogunate (Edo Period):
Hideyoshi had exiled the large Tokugawa clan from the area around Kyoto to the Kanto region in eastern Japan. The Taiko died in 1598, and by 1600, Tokugawa Ieyasu had conquered the neighboring daimyo from his castle stronghold at Edo (the future Tokyo).
Ieyasu's son, Hidetada, became shogun of the unified country in 1605, ushering in about 250 years of relative peace and stability for Japan. The strong Tokugawa shoguns domesticated the samurai, forcing them to either serve their lords in the cities, or give up their swords and farm. This transformed the warriors into a hereditary class of cultured bureaucrats.
Meiji Restoration and the End of the Samurai:
In 1868, the Meiji Restoration signaled the beginning of the end for the samurai. The Meiji system of constitutional monarchy included such democratic reforms as term limits for public office and popular balloting. With public support, the Meiji Emperor did away with the samurai, reduced the power of the daimyo, and changed the capital's name from Edo to Tokyo.
The new government created a conscripted army in 1873; some of the officers were drawn from the ranks of former samurai, but more of them found work as police officers. In 1877, angry ex-samurai revolted against the Meiji in the Satsuma Rebellion; they lost the Battle of Shiroyama, and the era of the samurai was over.
The Culture and Myth of the Samurai:
Samurai Culture: The culture of the samurai was grounded in the concept of bushido - "the way of the warrior." The central tenets of bushido are honor and freedom from the fear of death. A samurai was legally entitled to cut down any commoner who failed to honor him (or her) properly. A warrior imbued with bushido spirit would fight fearlessly for his master, and die honorably rather than surrender in defeat.
Out of this disregard for death, the Japanese tradition of seppuku evolved: defeated warriors (and disgraced government officials) would commit suicide with honor by ritually disemboweling themselves with a short sword.
Samurai Weapons: Early samurai were archers, fighting on foot or horseback with extremely long bows (yumi). They used swords mainly for finishing off wounded enemies.
After the Mongol invasions of 1272 and 1281, the samurai began to make more use of swords, as well as poles topped by curved blades called naginata, and spears.
Samurai warriors wore two swords, together called daisho - "long and short." The katana, a curved blade over 24 inches long, was suitable for slashing, while the wakizashi, at 12-24 inches, was used for stabbing. In the late 16th century, non-samurai were forbidden to wear the daisho.
Samurai wore full body-armor in battle, often including a horned helmet.
The Samurai Myth: Modern Japanese honor the memory of the samurai, and bushido still infuses the culture. Today, however, the samurai code is invoked in corporate boardrooms rather than on the battlefield.
Even now, everyone knows the story of the 47 Ronin, Japan's "national legend." In 1701, the daimyo Asano Naganori drew a dagger in the shogun's palace and tried to kill Kira, a government official. Asano was arrested, and forced to commit seppuku. Two years later, forty-seven of his samurai hunted down Kira and killed him, without knowing Asano's reasons for attacking the official. It was enough that he wanted Kira dead.
Since the ronin had followed bushido, the shogun allowed them to commit seppuku instead of being executed. People still offer incense at the graves of the ronin, and the story has been made into a number of plays and films.
Ansart, Olivier (2007) "Loyalty in Seventeenth and Eighteenth Century Samurai Discourse," Japanese Studies, 27:2, 139-154.
Collcutt, Martin (1996) "The 'Emergence of the Samurai' and The Military History of Early Japan," Harvard Journal of Asiatic Studies, 56:1, 151-164.
Hooker, Richard (1996), http://www.wsu.edu/~dee/TOKJAPAN/WARRING.HTM