Š™‘q‚Ì—ðŽj@Š™‘qŽž‘ã
The Kamakura period


Minamoto no Yoritomofs establishment of the Kamakura government

@@@Minamoto no Yoritomo (Œ¹—Š’©, 1147-99)gained victory over the Taira and established the first military government in Kamakura, which is also called Kamakura bakufu (1185/92-1333), Kamakura shogunate. The exact year of the start of this period is still contested, but major suggestions are:
  • 1180: Yoritomo first enters Kamakura and establishes his base here
  • 1185: Yoritomofs forces, under the command of Minamoto no Yoshitsune (Œ¹‹`Œo, 1159-89), finally defeat the Taira and he gains control of the country.
  • 1192: Yoritomo is given the title of seii tai shogun (ªˆÎ‘叫ŒR) by Emperor Go-Toba (Œã’¹‰H“Vc, 1180-1239).
Statue of Minamoto no Yoritomo
@@@Yoritomofs reasons for choosing Kamakura as his permanent base are believed to be, first, that the area had had a connection with the Minamoto family from the time of Yoriyoshi. Secondly, the strategic location of this region, surrounded as it is by hills on three sides and the ocean on the south, provided for defense against attack from the outside and for the control of the warriors in the east. For the next 150 years, Kamakura thrived as the political center of the military.
@@@In 1192, Yoritomo became seii tai shogun, a title that translates literally as gbarbarian-subduing generalissimo.h As such, one of his important tasks was to construct the city. He moved the Hachimangu Shrine from present-day Zaimokuza to its present site.
@@@The first of the government offices was the Samurai-dokoro (Ž˜Š), Board of Retainers, set up in 1180 to discipline and control the vassals. Next came the Kumonjo (Œö–⏊), Public Documents Office, which later, in 1184, was absorbed into the Mandokoro (­Š), Administrative Board, to deal with general government matters, finance, and management of the city of Kamakura. A third office, also in 1184, was the Monchujo (–⒍Š), Board of Inquiry, to hear and review claims and law suits.
Former site of Shochojuin Temple
@@@In Kamakura, the mansions belonging to Yoritomo's trusted and leading retainers were strategically located around the city. Yoritomo also refurbished Sugimotodera Temple and Egara Tenjin Shrine, and built such celebrated temples as Shochojuin (Ÿ’·ŽõŽ›‰@) and Yofukuji (‰i•ŸŽ›).




Feud between two brothers: Yoritomo and Yoshitsune

@@@In the course of stabilizing his government, however, the long-simmering feud between Yoritomo and his younger brother, Yoshitsune, finally erupted. Minamoto no Yoshitsune was manipulated by Go-Shirakawa Hoo (Œã”’‰Í–@‰¤, 1127-92) who was highly displeased with the military government for having become too powerful, Yoshitsune accepted a high position at court without first notifying Yoritomo in Kamakura. Such acceptance of high rank in court posed a danger to the newly-formed Kamakura government, because Yoritomofs first priority was unity created under his own command.
@@@After Minamoto Yoshitsune destroyed the Taira in 1185, he tried to return to Kamakura and plead his innocence, but was blocked at Koshigoe (˜‰z). Yoshitsune then submitted a series of oaths stating his complete loyalty to Yoritomo, but on the advice of Kajiwara Kagetoki (ŠŒ´ŒiŽž, ?-1200), all were disregarded. (Kagetokifs statements were taken as slander by many influential vassals who were sympathetic to Yoshitsune, and Kagetoki was later year ousted from the government). Yoshitsune sent a letter to Oe no Hiromoto (‘å]LŒ³, 1148-1225) while he was staying in Koshigoe, a letter that was to be his last message and is now referred to as Koshigoe-jo (˜‰zó), the Letter of Koshigoe.
@@@With all of his pleas now rejected, Yoshitsune was forced to return to Kyoto. Backed into a corner, he then received a decree from Emperor Go-Shirakawa to conquer Yoritomo and rose against him in 1185. Yoritomo, in response, dispatched a large army to Kyoto, and Yoshitsune was forced to flee yet again. But before he arrived in Hiraizumi(•½ò, in present-day Iwate Prefecture), he had to part from Shizuka Gozen (ÃŒä‘O, ?-?), his mistress. She had followed him but was captured at Mt. Yoshino (‹g–ìŽR) in Nara Prefecture and sent to Kamakura.
@@@There, within the grounds of Hachimangu Shrine, in the presence of Yoritomo and Masako, Shizuka bravely performed a dance, defiantly singing a song expressing her love for Yoshitsune. Later, Yoshitsune took refuge with the Fujiwara in Hiraizumi. This did not mean safety, however. In 1189 he and his followers were attacked and killed there by Fujiwara no Yasuhira (“¡Œ´‘׍t, 1155-89), who had been pressured by Yoritomo to carry out this act.


Second shogun:@Minamoto no Yoriie

Tomb of Minamoto no Yoritomo
@@@Upon Yoritomo's death in 1199, his eldest son, Minamoto no Yoriie (Œ¹—Š‰Æ, 1182-1204) succeeded him in 1202, becoming the second shogun. In that same year, Kajiwara no Kagetoki, one of Yoritomo's most trusted men, was purged from the bakufu, for he had always been at odds with the other retainers.
@@@Yoriie is said to have had an unstable character and was rendered powerless by his mother, Masako, and the Hojo family. They formed a council of senior officials at the head of the shogunal government, including Hojo Tokimasa, his son Hojo Yoshitoki (–kð‹`Žž, 1163-1224), Oe no Hiromoto and Miyoshi Yasunobu.
@@@When Yoriie became seriously ill in 1203, the council decided to divide the shogunal land-rights between his son Ichiman ([”¦, 1198-1203) and his younger brother, Minamoto no Sanetomo (Œ¹ŽÀ’©, 1192-1219) without even consulting Yoriie. Offended by the decision, Yoriie plotted against the Hojo, gaining support from his father-in-law, Hiki Yoshikazu (”äŠé”\ˆõ, ?-1203). The Hojo, however, forestalled Yoshikazu. On a pretext, Hojo Tokimasa invited him to a Buddhist service where he was killed, and the Hiki were then wiped out by the Hojo at Hikigayatsu (”äŠé‚ª’J), where Myohonji Temple (–­–{Ž›) now stands. The Hojo's scheme to do away with their rivals gradually succeeded. Yoriie was killed at Shuzenji Temple (C‘TŽ›).


Third shogun: Minamoto no Sanetomo

@@@After Yoriie, Minamoto no Sanetomo (Œ¹ŽÀ’©, 1192-1219), Yoritomofs second son, assumed the title of third shogun in 1203 at the age of thirteen. He is remembered in history more for his extraordinary talent in literature than for any ability in politics. Resentful of his powerlessness under the constant watch of both his mother, Masako, and his uncle, Tokimasa, he is said to have indulged in the literary arts and the aristocratic game of kemari (R‹f), a kind of kickball.
@@@When he was only fourteen years old, he began to learn poetry under Fujiwara no Teika (“¡Œ´’è‰Æ, 1162-1241), a famous court poet in Kyoto. An anthology of his works, Kinkai Wakashu (‹àžÅ˜a‰ÌW), The Collection of the Kamakura Ministry of the Right, was compiled by Teika after Sanetomofs death. His poems are direct and powerful, quite in contrast to the refinement and elegance of the court poems of the day.
Former site of
Hatakeyama residence
@@@Sanetomofs life witnessed many tragic events. The first was the power struggle between the Hojo and the Hatakeyama (”©ŽR), influential vassals from the time of Yoritomofs governance. In 1205, Hatakeyama Shigeyasu (”©ŽRd•Û, ?-1205) was accused of plotting a rebellion and was defeated and killed at Yuigahama Beach. His father, Hatakeyama Shigetada (”©ŽRd’‰, 1164-1205), inevitably involved in this affair, was then defeated and killed at Futamatagawa (“ñ–“ì, in present-day Yokohama). He is often held up as a paragon of the brave, loyal and modest warrior.
@@@Hojo Yoshitoki succeeded his father Tokimasa as the second regent, shikken (Ž·Œ ). Next came a battle in 1213 between the Hojo and the Wada, referred to as the Wada Gassen (˜a“c‡í). It originated as a trap laid by Yoshitoki, who hoped to eliminate his rival, the Wada clan. Wada Yoshimori (˜a“c‹`·, 1147-1213) and his family were powerful and fought bravely, but in the end were defeated and destroyed in 1213. Thus, Yoshitoki consolidated his position as second regent.


Sanetomofs unfulfilled dream and end of Yoritomofs direct lineage

@@@In spite of these circumstances, Sanetomo had the impressive temple complex of Daijiji (‘厜Ž›, now only memorial stone) in Juniso (\“ñŠ) built in 1212. Expanding his dreams further, Sanetomo ordered the construction of a ship large enough to sail to China. The ship, however, could not be floated due to the shallowness of the water at Yuigahama.
@@@At court, Sanetomo sought to rise from one high rank to another, and in 1218 finally attained the post of Udaijin (‰E‘åb), Minister of the Right. His life, however, like that of his predecessor, Yoriie, was ill-fated. On a snowy evening sometime in January 1219, as Sanetomo was leaving the grounds of the Hachiman Shrine after attending a ceremony to express his gratitude for promotion to the position of Minister of the Right, he was set upon by his nephew Kugyo (Œö‹Å, 1200-19) and murdered. Kugyo, in turn, was killed soon after by order of Yoshitoki. Who exactly masterminded the entire affair, however, is still unknown.
@@@Direct lineage from Yoritomo thus ended with the third succession. What the visitor here in Kamakura can now see is a memorial stone for the repose of Sanetomofs soul, along with one for his mother, Masako, at Jufukuji Temple.


Jokyu disturbance; Imperial rebellion

@@@Masako soon became a nun and was known as the gAma Shogunh (“ò«ŒR), literally, Nun Shogun. She then had no choice but to adopt Fujiwara no Yoritsune (“¡Œ´—ŠŒo, 1218-56), who was only two years old and a remote relative of the Minamoto, as the fourth shogun. After that, one nominal shogun followed another: the fifth, Fujiwara no Yoritsugu (“¡Œ´—ŠŽk, 1239-56), the sixth, Munetaka Shinno (@‘¸e‰¤, 1242-74), the seventh, Koreyasuo (ˆÒN‰¤, 1264-1326), the eighth, Hisaaki Shinno (‹v–¾e‰¤, 1276-1328), and the ninth, Morikuni Shinno (Žç–Me‰¤, 1301-33). Most were powerless and under the complete control of the Hojo regents. Some were forced to retire, and some were even sent back to Kyoto.
@@@In 1221, in Kyoto the retired Emperor Go-Toba and supporters of the imperial cause attempted to overthrow the Kamakura government. In response to this attempt, known as Jokyu no Ran (³‹v‚Ì—), the Jokyu Disturbance, Masako and her son, Yoshitoki, united the vassals to fight against the courtfs forces, and within a month claimed victory. Masako had successfully evoked loyalty among the retainers, it is said, by reminding them of their immense obligations to Yoritomo.
@@@The Kamakura government strengthened its guard against the court. Under Yoshitoki, it established the office of shogunal deputy, Rokuhara Tandai (˜Z”g—…’T‘è), in Kyoto to keep an eye on the court and assigned Hojo Yasutoki (–kð‘׎ž, 1183-1242), the eldest son of Yoshitoki, to this post.


Consolidation under Hojo regency

@@@Next, Yasutoki, upon the death of his father Yoshitoki in 1224, became the third shogunal regent. Under his leadership, the Kamakura government reached the height of its prosperity due to his success in introducing new measures that consolidated government power. In 1226, he established the Hyojoshu (•]’èO), Council of State. Eleven (later fifteen) men from various clans participated in it, deciding important personnel, political and judicial matters. Its main purpose was to avoid the hitherto erroneous and dictatorial leadership of the Hojo family. In 1232, Yasutoki proclaimed the Kanto Goseibai Shikimoku (ŠÖ“ŒŒä¬”sŽ®–Ú), the first codification of Warrior House Law, which consisted of 51 articles that spelled out the rights of the warrior class and clarified the duties and responsibilities of officials.
@@@Yasutoki also transferred the location of the bakufu twice: moving it first from Okura (‘å‘ ), where Yoritomo had established it, to Utsunomiya-zushi (‰F“s‹{’ÒŽq) close to the second torii of Hachimangu Shrine and named it Utsunomiya-zushi bakufu (‰F“s‹{’ÒŽq–‹•{). In 1236 it was moved again to a neighboring site and renamed Wakamiya-oji bakufu (Žá‹{‘å˜H–‹•{).
Site of Wakaejima Port, the oldest
artficial harbor that remains today
@@@Yasutoki also had Wakaejima Port (˜a‰ê]“‡) built and opened Asahinatoge Pass (’©”ä“Þ“»). He is further credited with consolidating Hojo rule. He died in 1242 and is buried at Jorakuji Temple (íŠyŽ›) in Ofuna.


Hojo Tokiyori: Road to Hojo dictatorship

@@@The fourth regent, Hojo Tsunetoki (–kðŒoŽž, 1224-46), a grandson of Yasutoki, died young. The fifth regent was Hojo Tokiyori (–kðŽž—Š, 1227-63), younger brother of Tsunetoki. He became regent in 1246, and in the following year eliminated the Miura family, who had been powerful vassals from the time Yoritomo had established the government. Tokiyori replaced the shogun, Fujiwara no Yoritsugu, with Prince Munetaka (@‘¸e‰¤, 1242-74). From that time on, the seat of the Kamakura shogunate came to be occupied by a succession of princes from Kyoto.
Kenchoji Temple
@@@Tokiyori had a reputation for being frugal and concerned with fairness in ruling the people. He had Kenchoji Temple (Œš’·Ž›) built. Although he handed over his position to Hojo Nagatoki (–kð’·Žž, 1229-64, the sixth regent) in 1256, he continued to wield substantial power. He died in 1263 and was buried in Meigetsuin (–¾ŒŽ‰@) in Kita-Kamakura.





Hojo Tokimune and Mongol invasions

@@@After Nagatoki came Masamura (­‘º, 1205-73), then Hojo Tokimune (–kðŽž@, 1251-84) who became the eighth shogunal regent in 1268. Tokimune twice faced Mongol invasions, once in 1274 and again in 1281. The first was launched because the Kamakura government had rejected the Mongol demand for submission. In response, Khubilai (or Kublai) Khan sent his forces to Hakozaki Bay (” è˜p) near Hakata in northern Kyushu. Fortunately, a storm did great damage to the invaders' ships, forcing them to retreat.
@@@An angered Khan later sent larger forces to Hakata Bay in 1281 because the Kamakura government not only again refused his demand for submission, but also beheaded his envoys. The government was driven into a corner in the face of the Khanfs large forces, but again a typhoon arose and forced the Mongol fleet to retreat.
@@@Victory at first seemed to produce a certain amount of national pride and to increase the prestige of the Hojo. Yet in reality the result was exactly the reverse. Since the war had been fought against foreign invaders, the government could not sufficiently reward its retainers for their sacrifices in the face of national emergency. Dissatisfaction prevailed among the retainers, damaging the popularity of the Hojo, and their power began to decline.
Engakuji Temple
@@@It was in such a situation that Tokimune, being an ardent follower of Zen Buddhism (‘T@), invited Mugaku Sogen (–³Šw‘cŒ³, 1226-86), a celebrated priest from Sung (‘v) dynasty China, and in 1283 had Engakuji Temple (‰~ŠoŽ›) built to console the souls of those who had died in the battles against the Mongols. Tokimune died in 1284 and was buried within the grounds of the same temple.




Sketch of the town, Kamakura

After Minamoto no Yoritomofs establishment
@@@In October 1180, Yoritomo entered Kamakura with his followers. When he had his mansion built in Okura, his major retainers followed suit, their estates standing along the hillsides for defense against attacks from outside. Gradually merchants and manufacturers set their dwellings in the area near the sea to take advantage of sea transportation to Wakaejima Port.
@@@Four borders bounded Kamakura: Mutsura (˜Z‰Y, the old pronunciation of Mutsuura), Kotsubo (¬’Ø), Inamuragasaki (ˆî‘º‚ªè) and Yamanouchi (ŽR‚Ì“à) to the east, south, west and north, respectively. Inside these boundaries was the city itself.
Gokurakujizaka Pass Daibutsuzaka Pass Asahinakiridoshi Pass
Kewaizaka Pass (Former) Kobukurozaka
Pass
Kamegayatsuzaka Pass
Nagoe Pass


@@@People came and went via nana kuchi (ŽµŒû), seven entrances, or nana kiridoshi (ŽµØ’Ê‚µ), seven passes. The former were Gokurakuji-kuchi (or -guchi) (‹ÉŠyŽ›Œû), Daibutsuzaka-kuchi (‘啧âŒû), Kewaizaka-kuchi (‰»ÏâŒû), Kobukurozaka-kuchi (‹•Ÿ˜CâŒû), Mutsura-kuchi (corresponding to Asahina-kiridoshi), Nagoe-kuchi (–¼‰zŒû), and Kotsubo-kuchi. The seven passes included Kamegayatsu-zaka (‹TƒP’Jâ) in addition to the above-named entrances with the exception of Kotsubo-kuchi.
@@@The more commercial activities increased, the more people flowed into Kamakura, bringing about prosperity but also disorder and confusion. In 1251 the government designated seven commercial districts: Omachi (‘å’¬); Komachi (¬’¬); Komemachi (•Ä’¬); the area around the crossroads of Kamegayatsu and Okura; the area at the top of Kewaizaka; and Wakae, where the government banned the tethering of cows on streets and ordered that the streets be kept clean.
@@@In 1265, the bakufu designated nine licensed commercial areas. Kamegayatsu and Kewaizaka were combined into Musashiojishita (•‘ ‘å˜H‰º), Wakae was replaced by Sujikaebashi (‹Ø‘Ö‹´), and Iomachi (‹›’¬) was added.
@@@As the number of legal and illegal residents increased, Kamakura seemed on the verge of chaos. City control was under the jurisdiction of the Mandokoro.
@@@In 1245, the bakufu prohibited the following acts: hunting with hawks within Kamakura; making a path without permission; extending walls towards streets; and extending onefs house over the ditch in front of it.
@@@In 1247, the bakufu road-checked wandering warriors, banishing them from Kamakura to maintain law and order.
@@@In 1261, retainers were ordered to refrain from building luxurious homes and were encouraged to repair bridges in the city and sweep clean the streets in front of their own houses. Abandonment of children and corpses of the diseased was also prohibited.


Visitorsf views of Kamakura
@@@People from the western part of Japan viewed Kamakura favorably. The Kaidoki (ŠC“¹‹L), the diary of a journey from Kyoto to Kamakura written in the 1220s, records that the sight of hundreds of boats at anchor here made it look like Otsu (‘å’Ã) in Omi Province (‹ß], in present-day Shiga Prefecture), and that the rows of thousands of houses resembled those of Oyodo (‘å—„) in Osaka. The diary further notes that Kamakura has the sea and hills, and is blessed with water and forests. The city was neither too big nor too small; streets were linked everywhere, and Kamakura was as prosperous as Kyoto.
@@@Another travel diary, the Tokan Kiko (“ŒŠÖ‹Is) refers to the magnificence of such structures as the residence of the shogun, Yofukuji Temple, and Hachimangu Shrine, as well as the Great Buddha in Hase.


Life of the warrior class
@@@The warriors' lives were dedicated to such martial arts as swordsmanship, archery, and horsemanship, which prepared them physically and mentally for any contingency their masters, especially the bakufu, might have to face. Loyalty, honor, bravery, and frugality were highly esteemed. In earlier times, when the warrior class was in its formative stage, it was through hunting that they first polished their military skills. Later, this practice turned into shooting at a target from the back of a running horse. Yabusame (—¬“L”n), a kind of ceremonial archery on horseback, was first held in 1187 under the auspices of Yoritomo in the grounds of Hachimangu Shrine, and is even today continued as an important and popular annual festival event attracting many on-lookers.
@@@Arms and swords were very important. Okazaki Masamune (‰ªè³@) (also known as Goro Nyudo Masamune), a skilled sword maker of the late 13th century, lived in Ogigayatsu.
@@@Warriors had simple meals twice a day, as did the common people. The mainstay was unpolished rice, accompanied by such items as pickled plums, dried jellyfish, beaten and salted abalone, as well as other seafood, venison, boar meat, certain kinds of birds, peaches, chestnuts, and walnuts. A typical meal served at a party along with unrefined sake included unpolished rice porridge with millet, jellyfish, Japanese ginger pickled in vinegar, cucumber rubbed with sake lee, grilled and salted sweetfish (ayu,ˆ¼), boiled eggplant, chestnuts, dried persimmons, and a type of carp called funa (•©).


Decline of the Kamakura government

@@@After Tokimune, the post of regent was successively occupied by Hojo Sadatoki (–kð’厞, 1271-1311, the ninth regent); Hojo Morotoki (–kðŽtŽž, 1275?-1311, the tenth regent); Hojo Munenori (–kð@é, 1259-1312, the eleventh regent); Hojo Hirotoki (–kðà†Žž, 1279-1315, the twelfth regent); Hojo Mototoki (–kðŠîŽž, ?-1333, the thirteenth regent); Hojo Takatoki (–kð‚Žž, 1303-33, the fourteenth regent); Hojo Sadaaki (–kð’匰, 1278-1333, the fifteenth regent) and the sixteenth and last regent, Akamatsu Moritoki (Ô¼ŽçŽž, 1295-1333).
@@@During the rule of Sadatoki, the Adachi family (ˆÀ’B) was destroyed in 1285, which set the stage for the beginning of a dictatorship by the head of the Hojo clan. The patrimonial head of the main branch of the Hojo, called tokuso (“¾@), held more power than did the regents.
@@@Under the regency of Sadatoki, the bakufu issued a decree, Einin no Tokuseirei (‰im‚Ì“¿­—ß), in 1297. It is thought to have been a well-meaning attempt on the part of the government to help retainers out of economic difficulties, but it did not work effectively.
@@@Takatoki, after retiring from the regency, wielded substantial control of the bakufu as Tokuso. He was said to be responsible for the corruption of the regime, for he is reputed to have spent his time engaging in dancing, dogfights and other such diversions, leaving the affairs of state in the hands of his men. Given these circumstances, the court in Kyoto, which had been watching for a chance to regain power, took action and, succeeded in 1333.


Collapse of the Kamakura government

Tomb of Hino Toshimoto
@@@In 1324, Emperor Go-Daigo's plot to overthrow the bakufu came to light. A subsequent investigation by the bakufu did not reach as far as the emperor himself, but several of the people who had masterminded the plot were arrested, as were some of the emperorfs influential attendants. Among them were Hino Suketomo (“ú–쎑’©, 1290-1332) and Hino Toshimoto (“ú–ìrŠî, ?-1332). Suketomo was exiled to Sado Island (²“n“‡) and executed. Toshimoto was soon released, but in the end was later executed at Kuzuharagaoka (Š‹Œ´ƒP‰ª) in 1332 when he again attempted to overthrow the bakufu. This was only one year before imperial rule was restored.
@@@The relationship between the court and the bakufu continued to deteriorate. Eventually, in 1331, Go-Daigo took up arms against Kamakura at Kasagi (Š}’u) in the southern part of Kyoto. The bakufu sent its army, headed by Ashikaga Takauji (‘«—˜‚Ž, later ‘¸Ž, 1305-58) and defeated the emperorfs forces. With the emperor arrested and exiled to Oki Island (‰BŠò“‡, in present-day Shimane Prefecture) in 1332, the matter seemed to be settled. But, Emperor Go-Daigo was rescued from Oki Island by his supporters, and in 1333 the loyalist tide reached its peak.
@@@Surprised at this turn of events, the bakufu again sent Takauji's army to Kyoto. This time, the ambitious Takauji knew which way the wind was blowing. Upon arrival in Kyoto he turned his back on the bakufu, and attacked and destroyed the Rokuhara Tandai, the bakufu's deputies stationed at Rokuhara in Kyoto.
Final resting place of the Hojo
@@@The next leading figure in the decisive downfall of the bakufu was Nitta Yoshisada (V“c‹`’å, 1301-38). Immediately after Takauji's defection, Yoshisada, who had been dissatisfied with the Hojo, also took up arms at Kozuke (ã–ì, in present-day Gumma Prefecture) against the bakufu. Dividing his forces into three groups, he attacked Kamakura--the first attack via Yamanouchi, the second via Kewaizaka Pass, and the third via Cape Inamuragasaki. On the 21st May 1333, Yoshisada's army at Inamuragasaki fought a fierce battle against the Kamakura forces, inflicting many casualties. The next day, as a result of this victory, Hojo Takatoki and his retainers, who numbered more than 700, committed suicide at Toshoji Temple (“ŒŸŽ›). This meant both the end of Hojo rule and the fall of Kamakura.@@(The end of this part)

Return to History of Kamakura  l  Early History of Japan

See next Kamakura in the Muromachi period