The feudal periods in Japan took place from the 12th through 19th centuries, and it marked an important period in the country's history. The rule of Japan by regional families and clans, as well as by the shogun (war lords) created a different sort of culture marked by a decrease in the power of the emperor as well as indifference in the ruling class. This part of history can be sorted into periods named for the ruling shogun families or shogunates.
The first time period started with the Kamakura Period, which began in 1192. During the reign of the Kamakura Shogunate, an invasion by the Mongols took place in which the Japanese were eventually able to repel the invaders. The problems the Mongol invasion caused finally led to the end of the line for the Kamakura Shogunate, which lost its reign in 1333.
At that time, the “Japanese Middle Ages” began, lasting through the next ruling family in the Muromachi Period. During the later years of this period, around 1542, a Portuguese ship ran aground on Japan's shores. This ship was carrying firearms, and firearm technology was introduced to Japan. This also led the way to other traders from Portugal and other European countries coming to Japan, and Christianity was also brought into the area at that time.