Where did the economic theory of "zero sum game" come from?

Much of what we think about free market economics probably comes from Adam Smith, and more recently Milton Friedman. Most of what we think about government influence over economics comes from John Maynard Keynes.
But there is an economic model that seems to be held by more people than the free marketeers, and the Keynesians combined. This is the “zero sum game” theory, which as you know, states that there is only a fixed amount of wealth in the universe, and that when one person gains a part of this wealth, somebody else is losing that part. Who is originator of this theory? Since the notion is so popular, why do we not learn about him in econ class?