Dark Ages vs history

Dark Ages and history both are nouns.

Word	Noun	Adjective	Verb	Adverb
Dark Ages	Yes	No	No	No
history	Yes	No	No	No

Dark Ages (noun)	history (noun)
the period of history between classical antiquity and the Italian Renaissance	the discipline that records and interprets past events involving human beings
	all that is remembered of the past as preserved in writing; a body of knowledge
	a record or narrative description of past events
	the aggregate of past events
	the continuum of events occurring in succession leading from the past to the present and even into the future