kingdom (realm ruled by a king and/or queen) / (figuratively): kingdom (realm or conceptual space where something is dominant)

stairs used in emergencies

state of emergency (unusually difficult or dangerous situation)

the island of Great Britain

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

study of history

historian

oral history

(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

historicism