The first period of the story of Chan is the most difficult to portray with any certainty, as the written records with which to build our story are incomplete and sketchy. In Zen's Chinese Heritage Andy Ferguson calls this period—from Bodhidharma's arrival in China at the end of the fifth century to the middle of the Tang dynasty in the mid eighth century—the "Legendary" period of Zen history. It is an apt title, for many of the stories of this time were written long after the events they describe, and it is difficult or impossible to separate legends created about the Zen ancients from what they may have actually said.
Regardless of the questionable origins of a story which may include both myth and facts, John Wu's statement about Bodhidharma holds true for all the Chan masters of this period:
Whether this and other stories about Bodhidharma possessed historical truth is far from certain. What is certain is that the Bodhidharma legend was believed in as a fact by the actual founders of the School of Zen in the Tang dynasty, when it had already become a living tradition.