Wisdom of the Ages (Knights of the Nine)

The Shield is located in Fort Bulwark, which is along the Cyrodil - Blackmarsh border, quite a ways straight east from Nocturnals Shrine. The Fort is inhabited by Conjurers who summon a wide variety of Daedra. After passing into the second area of the Fort, there is a prisoner in a cell on the right. Release the prisoner, now called Sir Thedret, and he will tell you "When the eyes of the Guardians are upon you, Julianos will show you favor." He will then head to the priory of the nine while you continue into a large room with 2 or more conjurers and several guardian statues. Eliminate the conjurers and turn a switch on each side of the statues to get them all facing the center, once that is done, stand in the center until the door to the left of the room unlocks. Go through it and follow the passage to another puzzle room. Stand on the switch in the center and take the item in the box (its random as far as I know). While standing on the switch, look around. One of the statues along the wall will have an image of an item from the box in front of it. If you do not know which statue the item you have goes to, guess and if you are right, the statue will turn. If not, the item goes back to the box in the center and the item that appears shows up on a different statue.

After completing the second puzzle, the lights dim and a door in the center opens, allowing you into the next room to claim the shield. Grab it and head back to the priory.