Following the Christian myth, Adam was the first architect and his son Cain was the first urbanist. Adam was the first architect because after all he had to build a shelter for himself, once he was expelled from the protective paradise. Cain, the Bible says, populated earth with his descendants, building the first city which he called Enoch after his son's name.
We can therefore assume that urbanism is—at least from this mythical perspective—a more recent art than architecture.