historical (adj.)

• absolute
• actual
• ascertained
• attested
• authentic
• authenticated
• autobiographical
• biographical
• certain
• certified
• confirmable
• confirmed
• corroborated
• demonstrable
• demonstrated
• determined
• documentary
• documented
• effectual
• established
• factual
• genuine
• historic
• historied
• incontestable
• incontrovertible
• indisputable
• indubitable
• irrefutable
• legendary
• positive
• provable
• proved
• real
• recorded
• reliable
• self-evident
• substantial
• substantiated
• sure-enough
• testable
• traditional
• true
• truthful
• unanswerable
• undeniable
• unimpeachable
• unquestionable
• validated
• veracious
• verifiable
• verified
• veritable