Origin of the Gray Prince is a quest in The Elder Scrolls IV: Oblivion. After becoming a combatant in the Arena, this quest can be started by talking to the reigning Grand Champion, Agronak gro-Malog in the Imperial City Arena Bloodworks, about his past.
After speaking to Agronak, he will give a key to the Hero so they can enter the last room. Head to Crowhaven, outside are a few skeletons. Defeat them and enter the fort. Simply follow the marker and find his father, Lord Lovidicus, he will be in the last room in the first level. Most of the way there is only one direction you can travel, so locating him should be fairly easy. The only other enemies inside the fort are animals like rats and wolves.
The Lord turns out to be a vampire. Fight and defeat - or sneak past - him and bring back the vampire's journal to Agronak to get the reward. Upon receiving the reward, Agronak will begin a self-loathing phase that continues through the final bout in the arena, which is with him. Agronak will just give up the fight and let himself be killed.
Agronak gro-Malog, the Imperial Arena Grand Champion, has sent me on a quest to find proof of his noble birthright. I must journey now to the west, to a place called Crowhaven, and begin my search. Gro-Malog has provided me with a key I will surely need, but even he is unsure what it opens.
I have entered Crowhaven. Somewhere inside I will unlock the truth that Agronak gro-Malog is searching for. I should be cautious, however. The fort has long since lost its noble trappings, and the presence of evil is unmistakable...
I have discovered the Journal of the Lord Lovidicus. It does indeed contain information about Agronak gro-Malog's birth, but proves he was the spawn of a vampire! Agronak won't be happy to hear this, but it is the proof he wanted. I must take the journal to him at the Imperial City Arena Bloodworks.
I have given the Journal of the Lord Lovidicus to Agronak gro-Malog. In return for my assistance, he has shared some of his combat knowledge.
- This quest cannot be completed after the Hero has challenged the Gray Prince, or become a Champion in the Arena, as he will be either dead or awaiting the battle.
- This quest is optional, and does not have to be completed in order to fight the Gray Prince and complete the Arena story line. However, if this quest is not completed, when the Hero challenges the Gray Prince to battle, he will fight like any other combatant.
- After the quest the Gray Prince will stand and die, instead of fighting, during the challenge in the Arena. He must be killed to leave the Arena, this counts as a murder, but not a crime. No bounty is placed on the Hero, nor are the Gray Prince's items considered stolen. This provides an easy way of joining the Dark Brotherhood.
- This is considered a murder because the Gray Prince does not become hostile to the Hero before he is attacked, which is the only check for assault and murder.