Is the Lich an actual lich?

As in was he a person/wizard before he ended up like... *that* and did the whole soul-connected-to-phylactery thing, or was he always like that from his current reincarnation?

I know he's the reincarnation of the catalyst comet that wiped out the dinosaurs (and the bomb/s that dropped), but did he used to be someone to an extent?