Heinrich Kemmler aka The Lichemaster was a character that turned up in a couple of early Warhammer Fantasy Battle scenarios. He was quite iconic in the early Warhammer days and I think carried on into 90s-era Warhammer but I'm not sure if he is still going in these days where the undead army has been split into the Hammer-inspired Vampire Counts and the Egyptian pulp goodness of the Tomb Kings.
This Ian Miller piece has curious composition because it was one long landscape orientation piece designed to be effectively a diptych, the right hand half formed the cover of Warhammer scenario/campaign pack "Terror of the Lichemaster" whereas the Orcs on the left and Mitteleuropa village formed the cover of "Blood On The Streets" which was a collection of cardstock buildings with a slim pamphlet detailing the inhabitants of a couple of Old World villages. This latter work was something of an odd fish as it was essentially an RPG supplement, prior to WFRP, that used WFB2 stats. Curious.
(Upon reflection I think I recall an earlier cover for Lichemaster which was painted by Gary Chalk. If I'm correct this would make the Miller work a later cover. I'll try and confirm this in the near future).
This "one artwork-two covers" arrangement explains the odd demarcation and separation of the foreground elements. Note the alien/surreal nature of the trees and foreground landscape - a similar device to the Blanche works I blogged about last year, showing us that the Warhammer World is not our world and even the small details look radically different.
Kemmler later made an appearance in "The Vengeance of the Lichemaster" in the Citadel Journal of Spring 1986 for which this is the John Blanche cover. In this scenario, he was pitted against the new Citadel/GW invention, Skaven, the Chaos Ratmen. I've never seen this Journal nor scenario but adverts claim it was a three-sided battle between Kemmler, the Skaven and Bagrian, the master of La Maisontaal whom I assume is the central figure in the russet-coloured robes.