Battle of Dan-no-ura
Final decisive battle of the Genpei War (1185), where the Minamoto clan defeated the Taira. A historical term; often referenced in Japanese history and literature.
See also: 壇ノ浦の戦い
The Taira clan was destroyed at the Battle of Dan-no-ura.
Same battle; 戦い is a more general word for 'battle', while 合戦 specifically refers to a large-scale battle or engagement.
Named after the location Dan-no-ura (壇ノ浦) in present-day Shimonoseki, Yamaguchi Prefecture, where the battle took place. 合戦 means 'battle'.