most of all, extremely

historic, historical / already-happened, past / former, old, traditional

oral history

historicism

historian

(Internet slang, especially anime and manga fandom) events or things from the past which one wants to whitewash/erase from history (due to it being embarrassing, poorly received, etc.); dark past

study of history

(historical) "Day of Public Duty for the Development of Asia": the first day of every month (1939–1942), when eating at restaurants was forbidden as part of the National Spiritual Mobilization Movement (国民精神総動員運動)

The spiritual world

corporate patriotism