Necronim: this is the only name anyone knows him by. Anyone else that might have known it are, as he says, "Long been dust and are better off for it." His real name is thus lost to the pages of history, forgotten by time, people, and even himself.
After being awakened from the nightmare of the Scourge, he cast aside everything he had been before...including his name and the man he had been. All that IS known of him is that he was barely twenty when taken by the plague, though his appearance now echoes that not at all.