[2] Porthan's legacy greatly influenced the rise of the national culture and romanticism of the early 19th century.
In 1754, at the age of 15, Porthan entered the Royal Academy of Turku (now University of Helsinki).
[5] He became a Fennophile and brought Finnish history-writing, study of mythology and folk poetry, and other humanistic sciences to an international level.
He instructed Kristian Erik Lencqvist (1761–1808) whose 1782 dissertation De superstitione veterum Fennorum theoretica et practica was a seminal study of historic Finnish customs.
by Sven Gabriel Elmgren and Josef August Schauman, 5 vols (Helsingfors: Finska Litteratur-Sällskapets tryckeri, 1859–73).