The major characteristic of Prester John tales from this period is the king's portrayal not as an invincible hero, but merely one of many adversaries defeated by the Mongols. But as the Mongol Empire collapsed, Europeans began to shift away from the idea that Prester John had ever really been a Central Asian king. At any rate they had little hope of finding him there, as travel in the region became dangerous without the security the empire had provided. In works such as "The Travels of Sir John Mandeville" and "Historia Trium Regum" by John of Hildesheim, Prester John's domain tends to regain its fantastic aspects and finds itself located not on the steppes of Central Asia, but back in India proper, or some other exotic locale. Wolfram von Eschenbach tied the history of Prester John to the Holy Grail legend in his poem "Parzival", in which the Prester is the son of the Grail maiden and the Saracen knight Feirefiz.