The Epoch of Unification (1568 - 1615 AD)

by J.S.A. Elisonas Editor's Note: This article was originally written for Japan Society's previous site for educators, "Journey through Japan," in 2003.

The century after the outbreak of the internecine Ônin War in 1468—the terminal phase of the Middle Ages in Japan—was an epoch of unbounded violence. The polity splintered into hundreds of autonomous entities engaged in mutual contention. The nation’s nominal sovereign, the emperor, was impoverished and politically impotent—a remote, isolated, and nebulous figure whose reign could best be described as metaphorical. The other key person in the moribund central government was the shogun, a general magnificently called the pillar of the military, who was a scion of the great warrior family of the Ashikaga. Theoretically the emperor’s delegate and chief support, historically the usurper of his power, the shogun had by the end of the fifteenth century been reduced to a feeble if not abject figure who was alternately a puppet in the hands of his supposed vassals and rear vassals or a fugitive from Kyoto, his capital city. The country was an arena where combat among great lords called daimyo (literally, “great names”), petty provincial barons, armed religious institutions, and other fractious elements was the order of the day.

The disorder that had overcome the nation was put to an end by three heroic figures—Oda Nobunaga (1534-1582), Toyotomi Hideyoshi (1537-1598), and Tokugawa Ieyasu (1543-1616)—who transformed Japan from a country plagued by political fragmentation, social upheaval, and military conflict into one that was united, secure, and peaceful. The epoch of unification over which they presided is commonly called the Azuchi-Momoyama period (1568-1615) after the sites of castles associated with them.

The first of the unifiers, Oda Nobunaga, was still in his teens when he succeeded his father as the lord of a domain in Owari Province (the area of Nagoya) in Central Japan. He spent much of the 1550s in fighting off various members of his extended family and their party-takers in the struggle for mastery over the entire province. From this vicious contest he emerged the winner in 1558 after killing his younger brother. In 1560 Nobunaga survived a severe external threat by leading his small force to victory over the much larger invading army of Imagawa Yoshimoto, his daimyo neighbor on the east, at the Battle of Okehazama. In 1567 he conquered Mino Province, to the north of Owari. Having thus become the daimyo of two large, productive, and strategically located provinces, Nobunaga was ready to enter the stage of national politics, and he signaled his intention to do so by adopting the slogan “the realm subjected to the military” as the emblem on his seal. In 1568 he embraced the cause of a pretender to the shogunate, Ashikaga Yoshiaki, and marched on Kyoto, where he installed his protégé in office, but not in power. Nobunaga used his special relationship with the new shogun to increase his own prestige and authority, reserving the dominant role for himself.

The protector bullied the shogun. For his part, Yoshiaki plotted against the formidable patron whom he had in the initial, passing flush of gratitude addressed as “My Father.” In March 1573, when a strong daimyo coalition seemed poised to destroy Nobunaga, the shogun entered the lists against him overtly. But the coalition’s lead actor Takeda Shingen, the lord of three provinces and portions of five others, died of disease, freeing Nobunaga to turn on its other members. In August he banished Yoshiaki, thereby ending the Ashikaga shogunate de facto after 237 years of a vicissitudinous existence. Before the end of September, two other principals of the coalition—Asakura Yoshikage, the daimyo of Echizen Province (now the greater part of Fukui Prefecture, on the Sea of Japan), and Azai Nagamasa, the lord of northern Ômi Province (on Lake Biwa)—had been defeated in battle and had committed suicide. Nobunaga assigned their conquered domains to his vassals.

These successes of the year 1573 significantly advanced Nobunaga’s ambition to subject the realm to his control. He was, however, beset on his flanks by an indomitable enemy, the armed confederations of the so-called Single-Minded or True Pure Land sect, a branch of Buddhism rooted in faith in the savior Amida. These provincial leagues were by no means disorganized bands of peasants. Rather, they were efficient organizations ready to take on all comers in the defense of their faith. At their head was the abbot of the great temple-citadel Honganji in Osaka, in effect the pontiff of a religious monarchy, who appointed administrators over entire provinces, issued mobilization orders for military campaigns, and formed strategic alliances with secular lords. The pontiff threw down the gauntlet in 1570. Heeding his call to action against the “enemy of the Buddhist Law,” the rural confederates of the Osaka Honganji fought Nobunaga tooth and nail, repeatedly mauling his armies even in his own home province, Owari. In 1574, local warriors in league with the Honganji killed the military governor newly installed by Nobunaga in Echizen, and that province came under the control of the Single-Minded sectarians. Nobunaga had to conquer Echizen all over again the next year, and he did so by letting loose a massive wave of terror on the populace. His troops were told that as they pushed forward, they were to scour the mountains and forests and cut down everyone they came across, men and women alike. Apart from the countless victims of these search-and-destroy missions, the confederates’ thousands of battle casualties, and the more than twelve thousand prisoners whom Nobunaga ordered to be killed, the toll suffered by the population of Echizen included many additional thousands taken away by force to other provinces. Not that the Honganji was intimidated by these atrocities and by the massacres of its adherents perpetrated by Nobunaga elsewhere. Supported and supplied by various lords inimical to him, the temple-citadel held out until 1580. Its surrender that autumn represented a great step forward in Nobunaga’s seemingly unstoppable march of conquest.

Nobunaga’s surge to power reached its high-water mark in the spring of 1582, when his armies destroyed another persistent enemy, the Takeda family, and absorbed its domains. (The Takeda had been in decline since 1575, when Nobunaga’s musketry slaughtered their troops at the Battle of Nagashino. Intent on “killing them all without a single friendly casualty,” Nobunaga had deployed his harquebusiers behind board screens, which gave them protection as they blasted successive attacking waves of the Takeda men with ferocious gunfire.) On incorporating the territories of that great eastern daimyo house, the realm under Nobunaga’s control comprised twenty-nine of traditional Japan’s sixty-six provinces and large parts of four others. It occupied a contiguous space that stretched on Honshû, the main island of the archipelago, from the Sea of Japan to the Pacific Ocean, covering Central Japan, and reached across the Inland Sea to the island of Shikoku. Nobunaga made it clear that he considered himself the supreme if not the sole authority in this realm, one subjugated, unified, and reconstituted by him.

After his triumph over the Takeda, the imperial court offered to make him shogun and even to “appoint him to any rank at all.” Apparently confident that he did not need the emperor’s validation of his status—that the empowerment he gave to himself was sufficient —Nobunaga politely but firmly refused to discuss these proposals. In June 1582, less than a month after declining the court’s offer to elevate him to the highest levels of titular authority, the self-confident ruler was dead, the victim of an assassin from the upper tier of his trusted vassals.

Although his death was sudden, Nobunaga left behind a solid platform for the regime of unification. It was Toyotomi Hideyoshi who inherited (or, rather, seized) that platform and built on it. A man of obscure origins but obvious talent, Hideyoshi rose in Nobunaga’s service from a menial to a general in charge of major operations. At the time of his lord’s murder in Kyoto, he was away campaigning on a distant front. Demonstrating great diplomatic, logistic, and tactical skills, Hideyoshi disengaged, rushed his army to the area of the capital city, and defeated the assassin, Akechi Mitsuhide, in battle within nine days of hearing the news. In 1583, he swept away those among Nobunaga’s former paladins who were bold enough to oppose him militarily; the rest submitted to his hegemony and became his vassals. To be sure, the greatest of them all, Tokugawa Ieyasu, fought a protracted military campaign against Hideyoshi in 1584-1585 before he, too, subordinated himself. In 1585, Hideyoshi finished another task begun but left unfinished by Nobunaga, that of “pacifying” the True Pure Land sect’s leagues and other Buddhist communities in Kii Province (south of Osaka) with arson and carnage. Later that year, he reduced all of Shikoku to fealty. In 1587, having assembled upwards of 200,000 men, Hideyoshi subjugated the nine provinces of Kyushu in an invasion that took only five weeks to complete victoriously. He then redrew the political map of Kyushu by uprooting various local lords from their ancestral territories and transplanting them elsewhere while he emplaced his current confidants and his old comrades-in-arms from as far away as the northern periphery of the Japan Alps in domains on the island. In other words, Hideyoshi used Kyushu as his stage for a grand puppet play, demonstrating that even great regional lords were nothing more than moveable objects in the hands of their supreme overlord.

On that stage the hegemon played the part of the national ruler as a bravura role, assuming the posture of extreme nationalism towards the Europeans and their Christian converts, who were concentrated on Kyushu. Portuguese traders and Jesuit missionaries had first come to Japan in the 1540s. At that time, some of the warring lords had seen a distinct advantage in protecting them, sought out their commerce, and even embraced their Catholic religion. The Christian mission, initiated in 1549 by the Basque priest (and future saint) Francis Xavier and supported by Japanese lords for their own, far from disinterested reasons, achieved a measure of success in certain limited parts of the country. By 1582, the Jesuits had made no fewer than 150,000 converts.

On conquering Kyushu, however, Hideyoshi proclaimed to the foreigners and their converts, “Japan is the Land of the Gods.” To destroy the shrines of those gods, along with the temples of the Buddhas, in the process of turning people willy-nilly into Christian sectarians “is unheard of,” Hideyoshi’s decree continued. Such actions being “miscreant,” he ordered their initiators, the Jesuit padres, to leave Japan. The Portuguese merchants were specifically exempted from this expulsion edict, as trade was “a different matter.” In the event, the missionaries were spared the worst for the time being. Hideyoshi did not enforce his decree against them, probably because he thought that the priests still had their uses as intermediaries with the Catholic traders. But he expropriated the overseas merchants’ habitual port of Nagasaki, legally a Jesuit colony since 1580, and made it a part of his direct domain. No doubt there was a healthy portion of self-interest behind the confiscation, but the action also helped to establish an important public principle. By these determinations in regard to the Europeans, Hideyoshi showed that the conduct of foreign affairs was no longer a regional matter, something that provincial lords engaged in. Henceforth, Japan’s external relations would be ruled from the center.

To be sure, Hideyoshi was not yet the master of the entire country—not when he conquered Kyushu in 1587, and not even when he destroyed his last great daimyo opponent, the Hôjô family of Odawara in the Kantô region, in August 1590. The vast northern provinces Mutsu and Dewa, a third of the total landmass of Honshû, remained beyond Hideyoshi’s compass. It took another fourteen and a half months before the huge armies set in motion by him finally subdued the Far North in the autumn of 1591. Not until then was all of Japan integrated under one system of authority.

Indeed, Hideyoshi’s integral realm was not confined within the traditional borders of the Japanese empire. It extended beyond them. During the conquest of the Far North, Kakizaki Yoshihiro, an enterprising samurai who ran a Japanese outpost in what was then known as Ezochi (Alien Territory) and is now called Hokkaidô, led a group of Ainu, the aboriginal people of that island, in the attack on the last independence-minded baron of Mutsu Province. Hideyoshi recognized that warrior’s contribution to the campaign by enfeoffing him as the lord of a domain in southern Hokkaidô and granting him the right to collect tariffs on trade with the island. With these dispositions Hideyoshi formalized the beginnings of Japanese colonization and exploitation of Hokkaidô. In the Tokugawa period, these activities, resisted though they were by the indigenous population, were to attain great economic importance.

The conquest of the Far North was consummated with yet another demonstration of paramount authority on the part of Hideyoshi. The local lords were either dispossessed or integrated into his regime. Those lucky enough to be confirmed in their possessions were by that very fact turned from regional rulers in their own right into Hideyoshi’s delegates, men invested by him with fiefs and serving at his sufferance. They were ordered to send their wives and children to reside in Kyoto, Hideyoshi’s capital city; to destroy all forts in their domains except for their own residential castles; and to carry out cadastral surveys in their fiefs as a basis for the assessment of productivity. These policies of the unification regime were already familiar to their fellow daimyo in the rest of Japan. Castle busting, land surveys, daimyo transfers, and even Hideyoshi’s most notorious policy, the so-called sword hunt in 1588 which deprived the agricultural population of weapons, were measures that had been applied in Nobunaga’s time on a provincial or regional basis. What was new was their systematic application on a national scale. In other words, once Hideyoshi had conquered the entire country, his policies became the law of the land.

Significantly, it was in October 1591, just as the last resistance in the Far North was being extinguished, that Hideyoshi issued his most sweeping, penetrating, and draconian edict, a decree regarding social status that divided the population into four classes—samurai, farmers, artisans, and merchants. Strict boundaries had not divided these four groups before. Farmers bore and used arms, and men who went about armed also engaged in farming; contrary to popular belief, there was no distinct samurai “class” in the Middle Ages. Even in Nobunaga’s castle town of Azuchi, a military man could pursue one of the trades and live among tradesmen. Hideyoshi’s measures governing change of status put a stop to this relative social fluidity. In practice, artisans and merchants were regarded as closely related groups, both of them being included under the common label of townspeople. Samurai, farmers, and townspeople, however, were mutually exclusive categories. The change of affiliation from one to another of these was strictly prohibited.

The samurai constituted the governing class. For the most part, they were compelled to withdraw from the countryside to the castle town, where they lived in segregated residential quarters. They retained the right to bear arms, something denied the other classes. The populace had been disarmed, settling one of the principal conflicts of the “country at war.” So the samurai held the monopoly on inflicting violence. Here Hideyoshi laid down the design plan for the rigid class system that matured under his successor regime, the Tokugawa shogunate, and lasted until that regime’s fall in 1868.

Unlike Nobunaga, Hideyoshi, a man of no known pedigree, was intent on obtaining legitimation through the imperial court. In 1585, he arranged to have himself adopted into the highest lineage of the court nobility, qualifying him to be appointed kanpaku, imperial regent. While this office, which originated in the ninth century and was all-important at court until the last part of the eleventh, retained no more than a titular function by the time Hideyoshi assumed it, his actual power again gave the regency real authority. As though to gild the lily, in 1587 Hideyoshi had himself appointed grand chancellor of state (daijô daijin), the highest ministerial rank stipulated in the ancient constitution of Japan. The newly ennobled regent and chancellor created a fitting entourage for himself when he translated his military vassals into members of the civil aristocracy, arranging court titles for his principal feudatories. In short, Hideyoshi breathed life into the empty form of the imperial government in order to use it for his own purposes.

By then into his fifties, Hideyoshi was childless. His long-awaited first son, born in 1589, died at the age of two. In early 1592 he therefore adopted his nephew Hidetsugu as his son and heir, passing on the office of imperial regent to him while keeping a firm hold on power. The unexpected birth of another natural son, Hideyori, in 1593 was a joyful event for Hideyoshi but had fatal consequences for Hidetsugu, who turned overnight from Hideyoshi’s expedient means of attaining his main objective—passing on the governing power to a member of his own family—into someone who stood in its way. In 1595 Hideyoshi forced Hidetsugu to commit suicide, executed his family and friends, and eradicated his progeny, following up this bloody purge by exacting oaths of loyalty to Hideyori from the leading daimyo. To ensure Hideyori’s succession was the major task entrusted to the council popularly known as the Five Great Elders, a group of the most important grandees of the realm that emerged at the time of Hidetsugu’s fall and developed into the top executive organ of Hideyoshi’s regime. Tokugawa Ieyasu was this group’s most powerful figure.

But the problem of the succession was not Hideyoshi’s sole concern, and his ambitions were not limited to Japan alone. With the Far North mere days away from complete subjugation by the armies of his vassals in the autumn of 1591, he ordered the daimyo to prepare for another great military effort. After Mutsu Province, there was nothing left to conquer in Japan. This time, Hideyoshi planned a foreign war of aggression—an invasion of Korea and China, with India and even “South Barbary” (wherever it was that the Portuguese came from) looming in his utterances as the distant objectives. Obviously, geography was not Hideyoshi’s strong suit; else he would have realized that his target list was too ambitious, that China was too big for his maw, and that India was beyond his horizon.

Hideyoshi, did, however, have the capability to inflict great damage and suffering on Korea. His expeditionary force of almost 160,000 men began landing at Pusan at the southeastern tip of the Korean Peninsula in May 1592. No more than three weeks from the start of the invasion, the Japanese captured Seoul, Korea’s capital; a month and a half later, they occupied P’yongyang; two months after that, they were in control of the entire northeastern quarter of the peninsula, all the way to the Yalu and Tumen rivers. These were rapid but ephemeral gains. The Japanese never obtained a secure hold on the Korean countryside, where guerrillas constantly harassed their lines of communication. The Korean fleet, superior to Hideyoshi’s naval forces in armament and leadership, commanded the sea and made the task of supplying their forward divisions exceedingly difficult for the Japanese. The tide turned when a relief army sent by China, Korea’s suzerain, intervened in force at the beginning of 1593, surprising and routing the invaders. By the summer, the Japanese had withdrawn to a string of forts along the coast of the peninsula’s southeastern corner. There some 80,000 of them remained on garrison duty for the next four years, while futile and in large part fraudulent negotiations were conducted. The Koreans were not given much of a say in the peace process. The presupposition of supremacy on China’s part, no less than delusions of grandeur and invincibility on Hideyoshi’s, meant that peace was not given a chance. When the Chinese emperor, far from responding positively to Hideyoshi’s list of demands, offered him nothing better than vassalage under the title “King of Japan,” the Japanese warlord decided to reinforce his expeditionary army and resume offensive operations in Korea.

In the second campaign of aggression, launched in August 1597, Hideyoshi deployed a land force of 140,000 men with the objective of occupying Korea’s southern provinces and creating a fait accompli—the country’s partition. Again, the Japanese enjoyed initial successes; again, the Chinese army blocked them on land and the Korean navy on the sea; again, they were forced to pull back to a fortress belt along the southern coastline. The second offensive was an even worse failure than the first, as Hideyoshi’s troops, under assault, were hard put to hold on to their bases on the coast. Nevertheless, even on his deathbed Hideyoshi refused to abandon his vain ambition and give the order to withdraw from Korea. Throughout, his troops dealt death and destruction. Not to mention combatants, tens of thousands of the innocent Korean populace—men, women, and children—were hunted down to be killed, mutilated, or enslaved by the Japanese troops, whose cruel acts burdened the history of relations between the two countries with a terrible legacy.

When Hideyoshi died in September 1598, the Five Great Elders brought the Japanese troops home from Korea, but the fissures latent in his inner circle came to the surface. Two parties formed among men made by Hideyoshi—the so-called generals’ clique made up of the likes of Katô Kiyomasa and other warhorses who had gained notoriety in Korea, and the so-called administrators’ clique led by Ishida Mitsunari, who had made his reputation not on the field of battle but on the rice fields where Hideyoshi’s nation-wide land survey was conducted. The outer lords, too, divided into parties and braced for a climactic military conflict, one where domination over Japan would be at stake. Safeguarding Hideyoshi’s heritage became a shibboleth, an empty slogan. His heir Hideyori was five years old, and the putative guardians of the Toyotomi family’s interests were governed by self-interest. In particular, Tokugawa Ieyasu kept an eye out for the main chance.

Ieyasu was of country baron stock, a cut below Nobunaga’s social status. Textbooks usually describe him as Nobunaga’s ally. In fact, Ieyasu took the utmost care to demonstrate his subservience to Nobunaga throughout their relationship. In 1582, after the defeat of the Takeda, Nobunaga “gave the two provinces Suruga and Tôtômi to Lord Ieyasu,” that is, invested him with those provincial domains (now combined in Shizuoka Prefecture) under conditions of vassalage. In 1590, after the defeat of the Hôjô of Odawara, Hideyoshi transferred Ieyasu from his old territories and enfeoffed him with six provinces in the Kantô region. Ieyasu took up his residence in Edo, at the time an insignificant small town, which he and his successors were to make into the world’s largest city—now called Tokyo.

Clever enough to content himself with playing a subordinate role under Nobunaga, Ieyasu again showed great astuteness when he acknowledged Hideyoshi as his overlord after fighting him to a draw in the Komaki-Nagakute campaign of 1584-1585. That Ieyasu profited from having adopted the status of a liegeman willingly is beyond dispute. The annual productivity of the domains that Hideyoshi granted him in the Kantô was estimated at 2,500,000 koku of rice (one koku equals 5.1 bushels), making Ieyasu Japan’s greatest daimyo. To be sure, he was just another daimyo vis-à-vis Hideyori and the corporate legitimacy of the Toyotomi regime. What really counted, however, was that Ieyasu and his party-takers mustered the bigger battalions in the showdown that came two years after Hideyoshi’s death.

Ieyasu provoked this conflict by bellicose actions that he sought to justify as initiatives taken in defense of the interests of the House of Toyotomi. The “generals’ clique” lined up behind him. In turn, the “administrators” drew up a manifesto denouncing Ieyasu’s unilateralism, his usurpations of authority, and his broken oaths. Many powerful lords of western Japan proclaimed their allegiance to the anti-Tokugawa cause, mobilized their armies, and marched eastward.

In October 1600, the “Eastern Army” commanded by Ieyasu and numbering some 90,000 clashed at Sekigahara in Mino Province with the 80,000 men of the “Western Army” led by Ishida Mitsunari. When one of its principal contingents not only deserted but attacked the “Western Army” in the middle of the combat, Ieyasu’s victory was assured. Along with the battle, he won the dominion over Japan.

In the aftermath of the Battle of Sekigahara, it was Ieyasu’s turn to reward his friends and reduce his enemies. He confiscated the domains of eighty-eight lords who had adhered to the “Western Army,” and reduced the holdings of five who had been hostile or had vacillated. The total estimated annual yield of these expropriations was 6,320,000 koku, that is, one third of the country’s calculated productivity. The vacated domains were appropriated by Ieyasu himself or redistributed to Tokugawa loyalists. And now it was Hideyori who found himself relegated to the status of just another daimyo.

In March 1603, when Ieyasu was appointed shogun by the emperor, his conquest was ratified by the land’s highest authority, and he became Japan’s legitimate ruler. This was the beginning of the national government called the Tokugawa shogunate. Two years later, in order to demonstrate that the office would be hereditary in his family, Ieyasu resigned the position of shogun, passing it on to his son Tokugawa Hidetada, although he continued to keep a forceful hand in affairs. Tokugawa shoguns were destined to rule Japan until January 1868, for a total of 265 years.

There remained a thorn in Ieyasu’s side, a potential focus of disunity to take care of: Toyotomi Hideyori. Hideyoshi’s son was growing up in the powerful citadel built by his father in Osaka on the site previously occupied by the Honganji. Reputed to be impregnable, Hideyori’s Osaka Castle proved not to be as formidable, after all, as the Single-Minded sect’s fortress had been in defying Nobunaga for ten years. In the winter of 1614, Ieyasu put the Toyotomi stronghold under siege; taking advantage of an armistice, he filled in its moats and laid bare its approaches; in the summer of 1615, he stormed it. Hideyori died in the flames of his father’s fatally weakened castle, and Japan was well and truly unified.