Oda Nobunaga in the context of "List of National Treasures of Japan (castles)"

The Muromachi period or Muromachi era (室町時代, Muromachi jidai), also known as the Ashikaga period or Ashikaga era (足利時代, Ashikaga jidai), is a division of Japanese history running from approximately 1336 to 1573. The period marks the governance of the Muromachi or Ashikaga shogunate (Muromachi bakufu or Ashikaga bakufu), which was officially established in 1338 by the first Muromachi shōgun, Ashikaga Takauji, two years after the brief Kenmu Restoration (1333–1336) of imperial rule was brought to a close. The period ended in 1573 when the 15th and last shogun of this line, Ashikaga Yoshiaki, was driven out of the capital in Kyoto by Oda Nobunaga.

From a cultural perspective, the period can be divided into the Kitayama and Higashiyama cultures (later 15th – early 16th centuries).

The Sengoku period (戦国時代, Sengoku jidai; Japanese pronunciation: [seŋ.ɡo.kɯ (d)ʑiꜜ.dai, -ŋo.kɯ-] lit. 'Warring States period') was the period in Japanese history in which civil wars and social upheavals took place almost continuously in the 15th and 16th centuries. The Kyōtoku incident (1454), Ōnin War (1467), or Meiō incident [ja] (1493) are generally chosen as the period's start date, but there are many competing historiographies for its end date, ranging from 1568, the date of Oda Nobunaga's march on Kyoto, to the suppression of the Shimabara Rebellion in 1638, deep into what was traditionally considered the Edo period. Regardless of the dates chosen, the Sengoku period overlaps substantially with the Muromachi period (1336–1573).

This period was characterized by the decline of the Ashikaga shogunate, the de facto central government, while the sengoku daimyo (戦国大名, feudal lords of the Sengoku period), local power-holders, acquired greater political influence. The people rebelled against the feudal lords in revolts known as Ikkō-ikki (Ikkō-shū uprising).

Toyotomi Hideyoshi (豊臣 秀吉; Japanese pronunciation: [to.jo.to.mʲi (|) çi.de(ꜜ).jo.ɕi], 27 March 1537 – 18 September 1598), otherwise known as Kinoshita Tōkichirō (木下 藤吉郎) and Hashiba Hideyoshi (羽柴 秀吉), was a Japanese samurai and daimyō (feudal lord) of the late Sengoku and Azuchi-Momoyama periods and regarded as the second "Great Unifier" of Japan. Although he came from a peasant background, his immense power earned him the rank and title of Kampaku (関白, Imperial Regent) and Daijō-daijin (太政大臣, Chancellor of the Realm), the highest official position and title in the nobility class. He was the first person in history to become a Kampaku who was not born a noble. He then passed the position and title of Kampaku to his nephew, Toyotomi Hidetsugu. He remained in power as Taikō (太閤), the title of retired Kampaku, until his death. It is believed, but not certain, that the reason he refused or could not obtain the title of shogun (征夷大将軍), the leader of the warrior class, was because he was of peasant origin.

Hideyoshi rose from a peasant background as a retainer of the prominent lord Oda Nobunaga to become one of the most powerful men in Japanese history. He distinguished himself in many of Nobunaga's campaigns. After Nobunaga's death in the Honnō-ji Incident in 1582, Hideyoshi defeated his assassin Akechi Mitsuhide at the Battle of Yamazaki and became Nobunaga's successor. He then continued the campaign to unite Japan that led to the closing of the Sengoku period. Hideyoshi became the de facto leader of Japan and acquired the prestigious positions of daijō-daijin and kampaku by the mid-1580s. He conquered Shikoku in 1585 and Kyūshū in 1587, and completed the unification by winning the Siege of Odawara in 1590 and crushing the Kunohe rebellion in 1591. With the unification of Japan complete, Hideyoshi launched the Japanese invasions of Korea in 1592 to initial success, but eventual military stalemate damaged his prestige before his death in 1598. Hideyoshi's young son and successor Toyotomi Hideyori was displaced by Tokugawa Ieyasu at the Battle of Sekigahara in 1600 which would lead to the founding of the Tokugawa Shogunate.

The Ashikaga shogunate (足利幕府, Ashikaga bakufu), also known as the Muromachi shogunate (室町幕府, Muromachi bakufu), was the feudal military government of Japan during the Muromachi period from 1336 to 1573.

The Ashikaga shogunate was established when Ashikaga Takauji was appointed Shōgun after overthrowing the Kenmu Restoration shortly after it had overthrown the Kamakura shogunate in support of Emperor Go-Daigo. The Ashikaga clan governed Japan from the Imperial capital of Heian-kyō (Kyoto) as de facto military dictators along with the daimyō lords of the samurai class. The Ashikaga shogunate began the Nanboku-chō period between the Pro-Ashikaga Northern Court in Kyoto and the Pro-Go-Daigo Southern Court in Yoshino until the South conceded to the North in 1392. The Ashikaga shogunate collapsed upon outbreak of the Ōnin War in 1467, entering a state of constant civil war known as the Sengoku period, and was finally dissolved when Shōgun Ashikaga Yoshiaki was overthrown by Oda Nobunaga in 1573.

Ikkō-ikki (一向一揆; "single-minded leagues") were armed military leagues that formed in several regions of Japan in the 15th–16th centuries, composed entirely of members of the Jōdo Shinshū sect of Buddhism. In the early phases, these ikki leagues opposed the rule of local governors or daimyō, but over time as their power consolidated and grew, they courted alliances with powerful figures in the waning Ashikaga shogunate until they were crushed by Oda Nobunaga in the 1580s.

The Ikkō-ikki mainly consisted of priests, peasants, merchants and local military rulers who followed the sect, but they sometimes associated with non-followers of the sect. They were at first organized to only a small degree. However, during the reforms of the monshu Jitsunyo, and further under his grandson Shōnyo, the temple network enabled more efficient and effective mobilization of troops when needed. The relationship between Hongan-ji and its monshu was complicated: some monshu, such as Rennyo, condemned the violence, others, such as Shōnyo and Kennyo, channelled it to further political aims.

Tokugawa Ieyasu (born Matsudaira Takechiyo; January 31, 1543 – June 1, 1616) was a Japanese samurai, daimyo, and the founder and first shōgun of the Tokugawa shogunate of Japan, which ruled from 1603 until the Meiji Restoration in 1868. He was the third of the three "Great Unifiers" of Japan, along with his former lord Oda Nobunaga and fellow Oda subordinate Toyotomi Hideyoshi. The son of a minor daimyo, Ieyasu once lived as a hostage under daimyo Imagawa Yoshimoto on behalf of his father. He later succeeded as daimyo after his father's death, serving as ally, vassal, and general of the Oda clan, and building up his strength under Oda Nobunaga.

After Oda Nobunaga's death, Ieyasu was briefly a rival of Toyotomi Hideyoshi, before declaring his allegiance to Toyotomi and fighting on his behalf. Under Toyotomi, Ieyasu was relocated to the Kanto plains in eastern Japan, away from the Toyotomi power base in Osaka. He built his castle in the fishing village of Edo (now Tokyo). He became the most powerful daimyo and the most senior officer under the Toyotomi regime. Ieyasu preserved his strength during Toyotomi's failed attempts to conquer Korea. After Hideyoshi's death and the Battle of Sekigahara, Ieyasu seized power in 1600.

The Matsudaira clan (松平氏, Matsudaira-shi) was a Japanese samurai clan that descended from the Minamoto clan. It originated in and took its name from Matsudaira village, in Mikawa Province (modern-day Aichi Prefecture). During the Sengoku period, the chieftain of the main line of the Matsudaira clan, Matsudaira Motoyasu became a powerful regional daimyo under Oda Nobunaga and Toyotomi Hideyoshi and changed his name to Tokugawa Ieyasu. He subsequently seized power as the first shōgun of the Tokugawa shogunate which ruled Japan during the Edo period until the Meiji Restoration of 1868. Under the Tokugawa shogunate, many cadet branches of the clan retained the Matsudaira surname, and numerous new branches were formed in the decades after Ieyasu. Some of those branches were also of daimyō status.

After the Meiji Restoration and the abolition of the han system, the Tokugawa and Matsudaira clans became part of the new kazoku nobility.

The Honnō-ji Incident (本能寺の変, Honnō-ji no Hen) was the assassination of Japanese daimyo Oda Nobunaga at Honnō-ji, a temple in Kyoto, on 21 June 1582 (2nd day of the sixth month, Tenshō 10). Nobunaga was on the verge of unifying the country, but died in the unexpected rebellion of his vassal Akechi Mitsuhide.

Nobunaga only had a few guards and retainers with him when he was attacked, ending his Sengoku period campaign to unify Japan under his power.Nobunaga's death was avenged two weeks later when his retainer Toyotomi Hideyoshi defeated Mitsuhide in the Battle of Yamazaki, paving the way for Hideyoshi to complete the unification of Japan.