The "feudal" period of Japanese history, dominated by the powerful regional families (daimyo) and the military rule of warlords (shogun), stretched from the 12th through the 19th centuries. The Emperor remained but was mostly kept to a de jure figurehead ruling position. This time is usually divided into periods following the reigning family of the shogun.
Kamakura Period
The Kamakura period (鎌倉時代?), 1185 to 1333, is a period that marks the governance of the Kamakura Shogunate and the transition to the Japanese "medieval" era, a nearly 700-year period in which the Emperor (天皇 tennō), the court, and the traditional central government were left intact but were largely relegated to ceremonial functions. Civil, military, and judicial matters were controlled by the bushi (samurai) class, the most powerful of whom was the de facto national ruler, the shogun. This period in Japan differed from the old shōen system in its pervasive military emphasis.
In 1185, Minamoto no Yoritomo defeated the rival Taira clan, and in 1192, Yoritomo was appointed Seii Tai-Shogun by the emperor; he established a base of power in Kamakura. Yoritomo ruled as the first in a line of Kamakura shoguns. However, after Yoritomo"s death, another warrior clan, the Hōjō, came to rule as regents for the shoguns.
 Japanese samurai boarding Mongol ships in 1281.
A traumatic event of the period was the Mongol invasions of Japan between 1272 and 1281, in which massive Mongol forces with superior naval technology and weaponry attempted a full-scale invasion of the Japanese islands. A famous typhoon referred to as kamikaze, translating as divine wind in Japanese, is credited with devastating both Mongol invasion forces, although some scholars assert that the defensive measures the Japanese built on the island of Kyūshū may have been adequate to repel the invaders. Although the Japanese were successful in stopping the Mongols, the invasion attempt had devastating domestic repercussions, leading to the extinction of the Kamakura shogunate.
The Kamakura period ended in 1333 with the destruction of the shogunate and the short reestablishment of imperial rule (the Kenmu restoration) under the Emperor Go-Daigo by Ashikaga Takauji, Nitta Yoshisada, and Kusunoki Masashige.
Thus, the "Japanese Middle Ages", which also include the Muromachi period and lasted until the Meiji Restoration, started with the Kamakura period.
Muromachi Period
The Muromachi period (室町時代 Muromachi-jidai) is a division of Japanese history running from approximately 1336 to 1573. The period marks the governance of the Ashikaga shogunate, also called Muromachi shogunate, which was officially established in 1336 by the first Muromachi shogun Ashikaga Takauji, who seized political power from Emperor Go-Daigo, ending the Kemmu restoration. The period ended in 1573 when the 15th and last shogun Ashikaga Yoshiaki was driven out of the capital in Kyoto by Oda Nobunaga.
The early years of 1336 to 1392 of the Muromachi period is also known as the Nanboku-chō or Northern and Southern Court period, as the Imperial court was split in two.
The later years of 1467 to the end of the Muromachi period is also known as the Sengoku period, the "Warring States period", a time of intense internal warfare, and corresponds with the period of the first contacts with the West, with the arrival of Portuguese "Nanban" traders.A group of Portuguese Nanban foreigners, including the missionary Francis Xavier 17th century, Japan.In 1543, a Portuguese ship, blown off its course to China, landed on Tanegashima Island Japan. Firearms introduced by Portuguese would bring the major innovation to Sengoku period culminating in the Battle of Nagashino where reportedly 3,000 arquebuses (the actual number is believed to be around 2,000) cut down charging ranks of samurai. During the following years, traders from Portugal, the Netherlands, England, and Spain arrived, as did Jesuit, Dominican, and Franciscan missionaries.
Azuchi-Momoyama Period
The Azuchi-Momoyama period (安土桃山時代 Azuchi-Momoyama-jidai) runs from approximately 1568 to 1600. The period marks the military reunification and stabilization of the country under a single political ruler, first by the campaigns of Oda Nobunaga who almost united Japan, achieved later by one of his generals, Toyotomi Hideyoshi. The name Azuchi-Momoyama comes from the names of their respective castles, Azuchi castle and Momoyama castle.
After having united Japan, Hideyoshi invaded Korea in an attempt to conquer Korea, China, and even India. However, after two unsuccessful campaigns toward the allied forces of Korea and China and his death, his forces retreated from the Korean peninsula in 1598.
The short period of succession conflict to Hideyoshi was ended when Tokugawa Ieyasu, one of the regents for Hideyoshi"s young heir, emerged victorious at the Battle of Sekigahara and seized political power.