Fashion is one area of history where we have real documentation existing to this day. In the 18th century (1700’s) there were hand sketched fashion plates, plus the king of France sent pattern dolls around the world.
The 19th century had photographs, advertisements, & catalogs. Museums contain ancient samples of real clothing dating from early man to present day. These samples are used to make today’s historical reproduction patterns.
Earlier eras are documented through archealogical artifacts, cave paintings, hieroglyphics, written text, cartoons, sketches, & paintings/portraits.
(photo: Regency fashion was influenced by artifacts found such as these paintings from the Egyptian tomb of Nebanum)