Slogram

Slogram was a traitor who lied to Ironhammer, misinforming him that B'hrian Bloodaxe had died, whereupon Ironhammer committed suicide. This news was untrue, however, and Bloodaxe survived until the Battle of Koom Valley, where he died trapped inside a cave with the then Diamond King of the Trolls, with whom he had met to forge a treaty that would be considered heresy by the majority of both sides had it been made public.

This is an extremely famous (and never-ending, to human ears) scene in the Dwarf opera Bloodaxe and Ironhammer.

Lady Sybil Ramkin compares the deeds of Dee to those of Slogram - a connection built upon by Rhys Rhysson the Low King - towards the end of The Fifth Elephant.