During the second half of the 16th century, Japan gradually reunified under two powerful warlords: Oda Nobunaga; and Toyotomi Hideyoshi. The period takes its name from Nobunaga’s headquarters, Azuchi Castle, and Hideyoshi’s headquarters, Momoyama Castle.
Japan in 1582, showing territory conquered by Oda Nobunaga in grey
Nobunaga was the daimyō of the small province of Owari. He burst onto the scene suddenly, in 1560, when, during the Battle of Okehazama, his army defeated a force several times its size led by the powerful daimyō Imagawa Yoshimoto. Nobunaga was renowned for his strategic leadership and his ruthlessness. He encouraged Christianity to incite hatred toward his Buddhist enemies and to forge strong relationships with European arms merchants. He equipped his armies with muskets and trained them with innovative tactics. He promoted talented men regardless of their social status, including his peasant servant Toyotomi Hideyoshi, who became one of his best generals.
The Azuchi–Momoyama period began in 1568, when Nobunaga seized Kyoto and thus effectively brought an end to the Ashikaga shogunate. He was well on his way towards his goal of reuniting all Japan in 1582 when one of his own officers, Akechi Mitsuhide, killed him during an abrupt attack on his encampment. Hideyoshi avenged Nobunaga by crushing Akechi’s uprising and emerged as Nobunaga’s successor. Hideyoshi completed the reunification of Japan by conquering Shikoku, Kyushu, and the lands of the Hōjō family in eastern Japan. He launched sweeping changes to Japanese society, including the confiscation of swords from the peasantry, new restrictions on daimyōs, persecutions of Christians, a thorough land survey, and a new law effectively forbidding the peasants and samurai from changing their social class.Hideyoshi’s land survey designated all those who were cultivating the land as being “commoners”, an act which effectively granted freedom to most of Japan’s slaves.
As Hideyoshi’s power expanded he dreamed of conquering China and launched two massive invasions of Korea starting in 1592. Hideyoshi failed to defeat the Chinese and Korean armies on the Korean Peninsula and the war ended only after his death in 1598.
In the hope of founding a new dynasty, Hideyoshi had asked his most trusted subordinates to pledge loyalty to his infant son Toyotomi Hideyori. Despite this, almost immediately after Hideyoshi’s death, war broke out between Hideyori’s allies and those loyal to Tokugawa Ieyasu, a daimyō and a former ally of Hideyoshi. Tokugawa Ieyasu won a decisive victory at the Battle of Sekigahara in 1600, ushering in 268 uninterrupted years of rule by the Tokugawa clan.