Sekigahara (battle site, 1600)
Refers specifically to the historical location and the famous Battle of Sekigahara in 1600, a turning point in Japanese history.
関ヶ原の戦いは1600年に起こった。
The Battle of Sekigahara took place in 1600.
decisive battle; critical battle
Figurative use derived from the historical battle; refers to any crucial, make-or-break confrontation or contest.
次の試合が優勝への関ヶ原だ。
The next match is the decisive battle for the championship.
This election is likely to be the decisive Sekigahara of the political world.
The company is finally facing the decisive showdown that will determine its fate.