Holy Grail 

Some commentators claim that Wolfram's Parzival dates from decades after Chretien's Perceval, while yet other commentators think that the works are contemporary. Like I said previously, the subject matter is an area where the beginners stray in at their peril. Nothing is "simple" about this subject matter (because of the uncertainty over dates and the different takes offered by the various authors) and it is no good trying to convey otherwise.