Moneychanger Guild of Neyer
The MGN is one of the most powerful organizations in the world as they are the world's main bank. Any other bank is surely in debt to this organization. The MGN tends to deal with only banks, kings, leaders, or large "corporations". Any other loan or banking is done with some other company who tends to borrow money from the MGN when they are in need. And it seems every bank (and king, for that matter) finds times where they are in "need".