 Josce 's grandson Fulk fitzWarin , who died in <unk> , is ostensibly the hero of a lost romantic poem called Fouke le Fitz Waryn . The work survives as French prose in a loose corpus of medieval literature known as the <unk> of England . However , it appears to confuse events of Fulk fitzWarin 's lifetime with those of his grandfather 's . Other errors in the work include <unk> some of the Welsh <unk> barons of King Henry I of England 's reign into nobles of William the <unk> 's time , and <unk> an entire generation of <unk> . Although scholars believe Fouke le Fitz Waryn draws on genuine tradition , the difficulty in separating the fitzWarin biographies makes it a problematic source . 
