Theseus
https://www.ancient.eu/article/209/theseus--the-minotaur-more-than-a-myth/
https://www.greekmythology.com/Myths/The_Myths/Theseus_Adventures/theseus_adventures.html
Saint George
https://en.wikipedia.org/wiki/Saint_George#Controversy
https://en.wikipedia.org/wiki/Saint_George_and_the_Dragon#Origins
https://en.wikipedia.org/wiki/Theodore_of_Amasea
Till Eulenspiegel
https://en.wikipedia.org/wiki/Till_Eulenspiegel#Origin_and_tradition
https://www.britannica.com/topic/Till-Eulenspiegel-German-literature

John Henry
https://en.wikipedia.org/wiki/John_Henry_(folklore)
https://www.forbes.com/sites/harrybinswanger/2013/11/20/john-henry-a-steel-drivin-man-and-a-luddite/#6367eefa3ae1
Jason
https://www.sciencealert.com/new-evidence-suggests-jason-and-the-golden-fleece-was-based-on-true-events
https://en.wikipedia.org/wiki/Jason

Merlin
https://en.wikipedia.org/wiki/Merlin
https://en.wikipedia.org/wiki/Myrddin_Wyllt

Odysseus
http://www.telegraph.co.uk/news/worldnews/europe/greece/7962445/Greeks-discover-Odysseus-palace-in-Ithaca-proving-Homers-hero-was-real.html

Imhotep
https://en.wikipedia.org/wiki/Imhotep#Mythification
https://www.britannica.com/biography/Imhotep

King Arthur
https://en.wikipedia.org/wiki/King_Arthur#Debated_historicity
http://www.history.com/news/ask-history/was-king-arthur-a-real-person
Robin Hood
https://en.wikipedia.org/wiki/Robin_Hood#Early_references
http://www.historic-uk.com/HistoryUK/HistoryofEngland/Robin-Hood/