The heads of the alliance are the ones giving them to you yes... but it's the people of the territories that voted to give them the right to do so... these artifacts were found centuries ago in a large vault by hero's of this land not much unlike the group you have assembled now. They were, or course, more powerful than you are now but they had each served there own kingdom for many years before uncovering the vault with such precious artifacts within... The nations themselves were once a single entity, yet many years of in-fighting caused a breakup of the land into their now respective territories. With each territory went an artifact thus insuring no more power went to one than the other. Many think this was done as well to keep a 'family' tie to each of the territories as well thus pretty much assuring that one day they would once again have to work together to solve a common problem. It now seems that time.... is now, and lies in the hands of you six adventurers!