SItes related to the historic Battle of Sekigahara in 1600.
The
Battle of Sekigahara was a decisive battle on October 21, 1600, that preceded the establishment of the Tokugawa shogunate (also called the Edo Period, 1600-1868). Tokugawa Ieyasu (who led the Eastern forces battling the Western forces) took three more years to consolidate his position of power over the Toyotomi clan and the various daimyō, but Sekigahara is widely considered to be the unofficial beginning of the Tokugawa shogunate, the last shogunate to control Japan. The shogunate lasted over 250 years and was a period of relative peace after centuries of almost continual warfare between the many warlords.
Its historic importance is compared to other battles such as Waterloo, Gettysburg, Stalingrad, and Hastings as changing the course of history.
In addition to the Gifu Prefecture website about the battle indicated above,
Wikipedia also has an extensive description of the battle and its consequences. There are also many books and articles available in multiple languages about this historic battle.