As a starting point for the questline, you have to speak to the prophet guy. At some point in the dialogue he asks if you are a worthy knight.

If you mention any of your accomplishments, he'll sarcastically say you don't need his help. The prophet only tells you how to find the relics if you choose the option "I have no claim to fame".

Then he compliments you for having a humble heart, but that sentence was nothing more than absurd hypocrisy.

I'm the Champion of Cyrodiil, the Hero of Kvatch, the Fighter's Master and the Arena's Grand Champion but I'm completely oblivious to how famous I am.

There's no way you're being honest when you say that.