His Royal Blood

Others think that the Holy Grail doesn't refer to a cup at all, but rather to the sangreal, or royal blood, of Jesus. This theory, popularized by The Da Vinci Code, states that the Grail served as a coded symbol to protect the bloodline of Jesus. (This theory is based on the belief that Jesus and Mary Magdalene were married and had children.) If the sangreal was actually a record of the descendents of Jesus, the entire power structure of the Catholic Church would crumble. However, most Biblical scholars say there are no historic documents which support such speculation.