As the acting "high priest" and supreme executive of the Moonlit Order, High Augur is an amazingly important position with amazingly simple requirements for the job. To become the High Augur, one must simply have the Staff of the High Augur. Simple, yes, but considering the current High Augur almost always hides the staff in some amazingly hidden location and takes that location to his grave, it can be very, very hard to claim the Staff (and so, the position).
One of the more famous people to hold the position was Theoric the Eversnide, who appears to have used a form of time travel to ask his future self where he found the Staff.