1) Japan developed a feudal system in the mid-1000s CE as the imperial government weakened and regional clans gained power. Farmers traded land to powerful warlords called daimyo in exchange for protection. Daimyo were served by loyal samurai warriors who lived by a code of honor.
2) From 1560-1600 CE, three powerful daimyo unified Japan - Oda Nobunaga used force, Toyotomi Hideyoshi used alliances, and Tokugawa Ieyasu completed the unification in 1600 and established a military government called the Tokugawa Shogunate.
3) The Tokugawa Shogunate ruled Japan peacefully and isolated it