The Sengoku Jidai, or "Age of Warring States" (1467 – 1615), occurred within the Muromachi period , and was the era during Japanese history that gave rise to the Samurai and the Samurai lords (Daimyo) as the true power brokers of medieval Japan after the passing of the Kamakura bakufu.
During the Sengoku Jidai, the Emperor officially the ruler of his nation and every Samurai lord (Daimyo) swore loyalty to him, however he was largely a puppet head, and ceremonial figure, and real power was wielded by the Shogun.
The Kamakura Shogunate which began the rise of the Samurai class, gave way to the Ashikaga Shogunate, but the new rulers failed to win or hold the loyalty of many of the more powerful Daimyo who’s fiefs were not in the general Kyoto vicinity.
The more powerful Daimyo absorbed the lands of their weaker rivals and became known as sengoku daimyo. The warlords then passed on their position of strength to their male heir and so the position of daimyo became hereditary unless challenged by ambitious subordinate commanders. The wealth of the daimyo came from commerce, trade, and taxes imposed on those peasants who farmed on their estates.
Localized conflicts grew and lead to the Onin War (1467-1477), which evolved from a dispute over shogunal succession, where the "eastern" army of the Hosokawa and its allies clashed with the "western" army of the Yamana clan. The conflict arose due to each side backing a different candidate for the position of shogun which was ironic because as in the case of the emperors, the Ashikaga Shogunate no longer had any real power. By the end of the war, there was nothing worth fighting over.
Power shift after the Onin War
In the west, the Ouchi clan fell after nearly a thousand years. The family had a turbulent history, sometimes backing the wrong side in Japan’s various crises. Early in the Sengoku period, they reached the peak of their power. Ouchi Yoshioki restored a Shogun and sent opposing armies packing.
His son was much weaker and less warlike. Betrayed by one of his own vassals, he committed suicide while under siege. He was avenged by another of his vassals, Mori Motonari, leading the Mori clan to take the Ouchi’s place of power.
In the east, a four-way struggle took place between the Uesugi, Takeda, Hojo, and Imagawa clans.
Decades of conflict tore the region apart as those clans vied for power. War, diplomacy, marriage, and assassination all played their part. There was seldom a clear leader in their struggles, and no-one could gain full domination. The Hojo, with their strong military organization, lasted the longest. However, even they were eventually brought low by a new force emerging from the chaos of war.
After nearly a century of political instability and warfare, Japan was on the verge of unification by Oda Nobunaga, who hailed from the province of Owari to dominate central Japan.
· In 1582, Oda’s reign was short lived and he was assassinated by one of his generals, Akechi Mitsuhide.
· Mitsuhide was defeated by Oda loyalist; Toyotomi Hideyoshi who sought to establish himself as Oda's successor after rising through the ranks of foot soldier to become one of Oda's most trusted generals.
· Toyotomi eventually consolidated his control over the remaining daimyo’s and ruled as “Imperial Regent” and not as Shogun.
· His reign was also short, but during his time, he attempted two invasions of Korea, and while successful at first, a number of setbacks ended in statement. His forces retreated from Korea in 1598 prior to his death that same year.
· Toyotomi appointed a group of the most powerful lords in Japan—Tokugawa, Maeda Toshiie, Ukita Hideie, Uesugi Kagekatsu, and Mori Terumoto to govern the nation as a “Council of Regents” until his infant son, Hideyori came of age.
· A tenuous peace lasted until the death of Maeda in 1599. Then intrigue involving Ieyasu Tokugawa and Ishida Mitsunari lead to war.
· The Battle of Sekigahara in 1600, during which Tokugawa and his allies, who controlled the east of the country, defeated the anti-Tokugawa forces, which had control of the west. Regarded as the last major conflict of the Sengoku period, Tokugawa's victory at Sekigahara effectively marked the end of the Toyotomi regime, the last remnants of which were finally destroyed in the Siege of Osaka in 1615.
The Tokugawa Shogunate was then established by Tokugawa Ieyasu after victory at Sekigahara, ending the civil wars and bringing the Sengoku Period to it's official end.
1543 Arrival of Europeans in Japan bringing muskets
1545 Night battle of Kawagoe
1549 Muskets first used in war at the Kajiki siege
1571 Destruction of the warrior monks of Mount Hiei by Nobunaga
1573 Death of Takeda Shingen
1574 Siege of the warrior monk castle of Nagashima
1575 Siege and battle of Nagashino with volley firing
1576 Building of Azuchi castle
1580 Surrender of Ikko-ikki headquarters of Ishiyama Honganji
1581 Siege of Tottori by starvation
1582 Murder of Oda Nobunaga, Battleof Yamazaki
1583 Battle of Shizugatake gives Hideyoshi much control
1584 Battles of Komaki and Nagakute
1586 Building of Osaka castle
1587 Invasion of Kyushu by Hideyoshi
1591 Siege of Kunoe – unification of Japan completed
1592 First invasion of Korea
1593 Japanese withdraw from Korea
1597 Second invasion of Korea
1598 Death of Toyotomi Hideyoshi and final withdrawal
1600 Battle of Sekigahara
1603 Tokugawa Ieyasu becomes Shogun
1615 Death of Toyotomi Hideyori at Osaka