Heinrich Kemmler is a great and feared Necromancer. During his unnaturally prolonged lifespan he has assembled a library, the greatest trove of necromantic lore outside Nagashizzar and had been advisor and counselor to kings and princes across the Old World. In the hills beyond Quenelles in Bretonnia his army had smashed the zombie legions of the Council of Nine, an alliance of nine powerful necromancers. In the dark woods beyond the town of Bogenhafen in the western Empire, he had overcome the three Vampire Wizards of Blutwald and all their armies of walking dead. In the crypts beneath castle Vermisace he had overcome the ancient Liche wizard and all his acolytes and was since known as The Lichemaster. But his ambitious rivals eventually succeeded in defeating the Lichemaster, driving him to the edge of death. His body was broken and his mind blasted.
He fled and wandered the Grey Mountains and Border Princes for many years as a half sane beggar. He eventually fled into the Vaults where he sought a weapon of great power rumoured to be hidden in the multiple tombs dotted in the mountains, some dating from the time before the Dwarfs and the Elves had walked those lands. Some quirk of fate eventually led him to the tomb of the long dead Krell.
Krell in life was a great lord of Chaos, slain many millenia ago. When Nagash came north to find the Crown of Sorcery and went to war with the man-god Sigmar he raised this great warlord and made him one of the Nine Lords of Nagash, his favoured generals, acolytes and lieutenants. When Nagash was defeated by Sigmar and his armies thrown back Krell took his legion and continued to plague the land for many years before finally being defeated and entombed. It is rumoured that Kemmler was guided by the hands of Nagash to raise Krell and join forces with him. Here Kemmler struck a pact with the Chaos Gods who restored him to his former power and in return he swore to sow destruction in their name.
The tales of these two monsters are many. In 2491 IC they attacked Brettonian abbey at la Maisontaal which contained a powerful artifact stolen from the Skaven. Meek Gnadoom's spell made the Kemmler and his undead army arrived there as allies Skaven, but during the battle trying to kill the necromancer, but they failed. It was only thanks to the skill and heroism of Duke Tancred of Quenelles that the Abbey wasn't destroyed utterly. Kemmler escaped and fled back in the Grey Mountains while the Skaven returned to Skavenblight with their prize. Tancred returned with much honour and spent the rest of his life chasing the Lichemaster. The Duke was eventually killed at the Battle of Montfort Bridge, smashing Kemmler's forces.
The Wood Elves remember Kemmler for the 'Winter of Woes', a season when Kemmler raised a huge army from the many cairns in the forest, ancient human burial mounds long forgotten that were site of great mystical energy closely linked with the health of the Elves woodland home. By attacking in winter the Elves were at their weakest and it was only thanks to the great and venerable treeman Durthu who roused the native wood spirits that the necromancer was defeated, and not before he caused great swathes of devestaion to the forest.