Emperor Renburn is a non-playable character who appears in the cut scenes of Forsburn's chapter and is mentioned in Zetterburn's chapter in Story Mode. He was killed before the events of the game began, and only appears in a Story Mode cutscene as a corpse.
His assassination was done with a sword identical to that of Forsburn's making Forsburn the obvious suspect. Forsburn was framed for his murder, which was likely committed by his own council instead as part of a conspiracy, as Forsburn and his loyal spy had suspected.
After his death, Minister of Trade Loxodont was to be crowned the new Emperor. The Fire Council then convinced Zetterburn that this was his father's wish.