Tessalar wants you to recover the Axe of Balthazar so they can perform the proper ceremonies for their new Herd Leader.  It appears some nasty little Dark Dwarves did a little looting during this crisis and made off with the "Axe of Kings".  Of course he doesn't want to take any chances on the axe being a fake and you must take it to Dadeross on Dagger Wound Island for authentication. If Dadeross confirms you have the correct axe he will pen a letter of authentication. Once all is verified and Tessalar is satisfied, Masul in the Merchant house, where the Council is situated in Ravenshore , will promote your Minotaurs. Now, as for finding the axe.  It is not too hard to locate in the Dark Dwarf Compound (located in the chest at #1) in  Alvar however, those nasty little boulders blocking your way can be a royal pain in the banuska. (Not to mention this has to be the longest, most drawn out promotion quest with the running back and forth between maps so incredibly far apart!)