Rift Quest:Relics of the March Warden  

You can pick this quest up at the beginning of the Iron Tomb. The Staff of Derribec, Horn of Humbart, and Targe of Laric can all be found off of the second boss event in the instance. Each boss will drop one of the items in turn. When you finish the quest bring these relics to the Faceless Man or Shyla Starhearth depending on your faction for a nice ring.