The story of the life and death of Jesus Christ is well-documented and well-known. According to Grail legend, however, the story is a lie.
What happened was this: on the cross, Jesus was fed a soporific drug to put him in a deathlike coma. He was taken down from the cross and secreted away. His body was tended to, his wounds were cleaned, and after a few days he awoke. The story of the resurrection was put forth as a way to distract people from the real Son of God so that he would be allowed to live in peace. He married a woman named Mary and had several children. He died in actuality when he was 43 years old, run down by an offal cart.
His offspring was still considered part of the divine lineage, and a group immediately sprang up to protect them. This group came to be called The Grail, and their purpose was to make sure that the blood of Christ was neither watered down nor polluted. Unfortunately, this meant a prodigious amount of inbreeding.
Over the next two millennia the Grail grew both in size and in power. By the 20th Century, they were a global superpower, hidden in the shadows. They held the reins to all the nations of the world, and could exert power on the leaders of the world's most powerful governments. And they had a plan.
The plan was simple - to start a nuclear war in the year 2000. The first volley is fired on January 1st. Within two weeks, the world is in chaos. Nations are disintegrating, uniting and breaking up, and the ultimate destruction of mankind seems to be inevitable.
This is where the Messiah is introduced. He exerts his divine power, and war is averted. A new era of humanity begins, ruled by God-Kings. And the Grail.
The Messiah, however, was an inbred idiot.
This didn't matter, though. The Grail had prepared everything, it was going to go like clockwork. Until the Grail, its resources and its purpose were hijacked by Starr.
Formerly the Sacred Executioner, later the Allfather, Starr turned the Grail into his own personal weapon of revenge against Jesse Custer. Starr had wanted to replace the idiot Messiah with Custer, who was tall and handsome and who actually did have a divine power. Custer wouldn't go along, and scarred Starr's head, making it look disturbingly like a giant penis.
Starr's pursuit of Custer led to being sodomized in a back alley, the loss of his leg, the loss of an ear and eventual loss of his genitals, and so his goal changed as well. He went from wanting to use Custer in his plans for Armageddon to simply wanting to kill Custer out of revenge. His plans eventually led to the utter decimation of the Grail's military forces to the point where Starr was only able to put together a force of about two dozen men to take down Custer at the Alamo. The rest of the Grail's resources, the deep cover operatives, simply ignored Starr's order.
Finally, Starr ordered the death of the Grail ruling council at le Saint-Marie, and lost most of his men before finally killing Jesse Custer. Nearly moments later, Starr himself was killed by Custer's girlfriend, Tulip.
Thus the Grail was destroyed.