The came at the end of the Warring States Period in Japan, when the political unification that preceded the establishment of the Tokugawa shogunate took place. It spans the years from approximately 1568 to 1603, during which time Oda Nobunaga and his successor, Toyotomi Hideyoshi, imposed order upon the chaos that had pervaded since the collapse of the Ashikaga Shogunate. The name of this period is taken from Nobunaga's castle, Azuchi Castle, in the present-day town of Azuchi, Shiga Prefecture and Hideyoshi's castle, Momoyama Castle (also known as Fushimi Castle), in Kyoto.
In broad terms, this period begins with Nobunaga's entry into Kyoto in 1568, when he led his army to the imperial capital in order to install Ashikaga Yoshiaki as the 15th, and ultimately final, shogun of the Ashikaga shogunate, and lasts until the coming to power of Tokugawa Ieyasu after his victory over supporters of the Toyotomi clan at the Battle of Sekigahara in 1600.
Nobunaga, who had prepared over a period of years for just such an opportunity by establishing an alliance with the Azai in northern Omi and then conquering the neighboring province of Mino, now marched toward Kyoto. After routing the Rokkaku clan in southern Omi, Nobunaga forced the Matsunaga to capitulate and the Miyoshi to withdraw to Settsu. He then entered the capital, where he successfully gained recognition from the emperor for Yoshiaki, who became the 15th Ashikaga shogun.
Nobunaga had no intention, however, of serving the Muromachi bakufu, and instead now turned his attention to tightening his grip on the Kinai region. Resistance in the form of rival daimyo, intransigent Buddhist monks, and hostile merchants was eliminated swiftly and mercilessly, and Nobunaga quickly gained a reputation as a ruthless, unrelenting adversary. In support of his political and military moves, he instituted economic reform, removing barriers to commerce by invalidating traditional monopolies held by shrines and guilds and promoting initiative by instituting free markets known as rakuichi-rakuza.
By 1573 he had destroyed the alliance of Asakura and Azai clans that threatened his northern flank, obliterated the militant Tendai Buddhists monastic center at Mount Hiei near Kyoto, and also had managed to avoid a potentially debilitating confrontation with Takeda Shingen, who had suddenly taken ill and died just as his army was on the verge of defeating the Tokugawa and invading Oda's domain on its way to Kyoto.
Even after Shingen's death, there remained several daimyo powerful enough to resist Nobunaga, but none were situated close enough to Kyoto to pose a threat politically, and it appeared that unification under the Oda banner was a matter of time.
During the period from 1576 to 1579, Nobunaga constructed on the shore of Lake Biwa at Azuchi (in present-day Shiga Prefecture) Azuchi Castle, a magnificent seven-story castle that was intended to serve not simply as an impregnable military fortification but also as a sumptuous residence that would stand as a symbol of unification.
Having secured his grip on the Kinai region, Nobunaga was now powerful enough to assign his generals the task of subjugating the outlying provinces. Shibata Katsuie was given the task of conquering the Uesugi clan in Etchū, Takigawa Kazumasu confronted the Takeda in Kai, and Hashiba Hideyoshi was given the formidable task of facing the Mori in the Chūgoku region of western Honshū.
In 1582, after a protracted campaign, Hideyoshi requested Nobunaga's help in overcoming tenacious resistance. Nobunaga, making a stop-over in Kyoto on his way west with only a small contingent of guards, was attacked and killed by one of his own disaffected generals, Akechi Mitsuhide.
Quickly negotiating a truce with the Mori before they could learn of Nobunaga's death, Hideyoshi now took his troops on a forced march toward his adversary, whom he defeated at the Battle of Yamazaki, less than two weeks later.
Although a commoner who had risen through the ranks from foot soldier, Hideyoshi was now in position to challenge even the most senior of the Oda clan's hereditary retainers, and proposed that Nobutada's infant son, Sanpōshi (who became Oda Hidenobu), be named heir rather than Nobunaga's adult third son, Nobutaka, whose cause had been championed by Shibata Katsuie. Having gained the support of other senior retainers, including Niwa Nagahide and Ikeda Itsuoki, Sanpōshi was named heir and Hideyoshi appointed co-guardian.
Continued political intrigue, however, eventually led to open confrontation. After defeating Shibata at the Battle of Shizugatake in 1583 and enduring a costly but ultimately advantageous stalemate with Tokugawa Ieyasu at the Battle of Komaki and Nagakute in 1584, Hideyoshi managed to settle the question of succession for once and all, to take complete control of Kyoto, and to become the undisputed ruler of the former Oda domains. Daimyo of Shikoku Chōsokabe clan surrendered to Hideyoshi in July, 1585. Daimyo of Kyushu Shimazu clan also surrendered two years later. He was adopted by the Fujiwara family, given the surname Toyotomi, and granted the title Kanpaku in representing civil and military control of all Japan. By the following year, he had secured alliances with three of the nine major daimyo coalitions and carried the war of unification to Shikoku and Kyūshū. In 1590, at the head of an army of 200,000, Hideyoshi defeated the Hōjō clan, his last formidable rival in eastern Honshū. The remaining daimyo soon capitulated, and the military reunification of Japan was complete.
The surveys, carried out by Hideyoshi both before and after he took the title Taiko, have come to be known as the "Taikō surveys" (Taikō kenchi).
He also attempted to provide for an orderly succession by taking the title Taikō, or "retired Kanpaku," in 1591 and turned the regency over to his nephew and adopted son Toyotomi Hidetsugu. Only later did he attempt to formalize the balance of power by establishing administrative bodies. These included the Council of Five Elders, who were sworn to keep peace and support the Toyotomi, the five-member Board of House Administrators, who handled routine policy and administrative matters, and the three-member Board of Mediators, who were charged with keeping peace between the first two boards.
Main article: Japanese invasions of Korea (1592-1598)
Hideyoshi's last major ambition was to conquer the Ming Dynasty of China. In April 1592, after having been refused safe passage through Korea, a flourishing kingdom which enjoyed an alliance with Ming China, he sent an army of 200,000 to invade and pass through Korea by force. During the Japanese invasions of Korea (1592-1598), the Japanese occupied Seoul by May of 1592, and within three months of invading reached Pyongyang together with large numbers of Korean collaborators who at first viewed them as liberators from the corrupt aristocracy. The king of Korea fled, and the two princes were captured by Kato Kiyomasa.
The king of the Joseon Dynasty turned to China for military support, and, with Chinese intervention, the Japanese forces were forced to retreat as far south as Seoul by January 1593. The main generals in Korea have already been killed by a Japanese army. Therefore, A Chinese emperor sent admiral Chen Lin and Li Rusong to aid the Koreans. Li Rusong banished Japan from the Korean peninsula northern part. A Japanese army gathered in Seoul, and counterattacked to China. However, The Korean admiral Yi Sun-shin succeeded in attacks on the Japanese supply ships, and proceeded to cut off the Japanese supply line. Therefore, a Japanese army that had become a food scarcity started peace talks with China.
During peace talks, Hideyoshi demanded a division of Korea, free-trade status, and a Chinese princess as consort for the emperor. The Chinese saw no reason, however, to treat the invaders as equals, and, the Japanese requests denied, peace efforts reached an impasse. A second invasion began in 1597, but had far less success as the Japanese met with greater Korean resistance, and it was eventually terminated abruptly with Hideyoshi's death the following year in 1598, as Japanese commanders hurried home to the battles that were likely to ensue for control of the shogunate.
The art of the tea ceremony also flourished at this time, and both Nobunaga and Hideyoshi lavished time and money on this pastime, collecting tea bowls, caddies, and other implements, sponsoring lavish social events, and patronizing acclaimed masters such as Sen no Rikyū.
Hideyoshi had occupied Nagasaki in 1587, and thereafter sought to take control of international trade and to regulate the trade associations that had contact with the outside world through this port. Although China rebuffed his efforts to secure trade concessions, Hideyoshi commercial missions called to present-day Malaysia, the Philippines, and Thailand in Red seal ships were successful. He was also suspicious of Christianity in Japan, which he saw as potentially subversive and some missionaries were crucified by his regime.
Nobunaga, known for his ruthlessness, is the subject of the first; Hideyoshi, known for his resourcefulness, is the subject of the second; and Ieyasu, known for his perseverance, is the subject of the third verse.