Hagar Olavsson of Clan Ironwood (better known by his moniker Hagar the Red for his distinctive red hair and beard) was an Imperial Wars-era Dwarf Artificer who overtook the Veg Darul satellite town of Annan Veg for about a decade while the Dwarf military forces were occupied with assisting in the Imperial war effort. His short reign as warlord was eventually ended when the army of Manzil invaded the Dwarven Mountains and annexed them, during which he was captured and executed when he attempted to fight back.
According to myth, he left behind a massive treasure hoard in the caves on the outskirts of the ruined city which may even contain such lost treasures as Sherez's Wondrous Lantern, but there has been nobody that has survived going deep enough into the ruins to confirm or deny it. His personal fortress, Annan Veg, is also lost somewhere underneath what is now the Daemon City.
It is discovered during the events of Beneath the Mountain that Hagar had kept himself alive as a demi-Lich using his technological prowess, existing as a still-living brain in an elaborate mechanical body, able to control every facet of Annan Veg from his daunting Throne of Brass as if it were a part of himself. It was also discovered that he has been mutilating individuals captured by his followers, lobotomising them, then removing their nervous systems and implanting them, still living, into biomechanical abominations, each powered by a soul gem containing the soul of the individual - this having been a refinement of the same process he used to transform himself into a machine.