Start point: Camelot Castle
To start: Speak to King Arthur
Quest length: Long
Minimum requirements: Must have completed Merlin's crystal, Must defeat a lvl-126 Black Knight Titan
Members only: Yes Items needed: Excalibur sword from the Merlin's Crystal quest. You must done this quest before trying to complete the Holy Grail quest. If you have not got the excalibur anymore , then you can get one by talking to the lady of the lake again Reward: 3 quest points and some prayer exp.
King Arthur: Will tell you to talk to Merlin . Merlin will tell you to talk to the High Priest on Entrana or Sir Galahad who is living in a two story house on the outside west edge of McGrubor's wood.
Entrana: First deposit any armour and weapons before going to Entrana. When you go there , go to the church and talk to High Priest.
Sir Galahad: Go to his house and talk to him, he will give you a napkin.
Whistle: After you get the napkin , go to Draynor Manor. Go to third floor and retrieve two magic whistles.
Black Knight Titan: Take Excalibur, whistles, food, armour and cure potion with you. Go to Brimhaven, carry on west until you find poison scorpions. Now head north and you should see a square plot of stone. Stand on this and blow a whistle. You are now teleported to way the Holy Grail is.
To go further, you must kill the Black Knight Titan lvl 146. You must use Excalibur to kill him.
Castle: To get into the castle you must first talk to the Head Fisherman. Go back to the castle and find the bell. Ring the bell and you teleported into the castle. The King: Talk to the king there and he will tell you about his son. Once you finished talking to the king , blow your whistle again and this will teleport you back to the square Plot.
Golden Feather: Go back to King Arthur and talk to him. He will give you the golden feather. Son: He is found in Goblin Village. Find the sacks and prod them. Give him a whistle. Claiming your reward: Go back to the castle where the Holy Grail is and speak to the King again. Go upstairs and take the Holy Grail and then back to Camelot to speak to King Arthur again.