On May 5th, 1818, Karl Marx, hero of the international proletatiat, was born. His revolution of Socialist theory reverberates throughout the world carries on to this day, in increasing magnitude. Every passing day, he is vindicated. His analysis of Capitalism, development of the theory of Scientific Socialism, and advancements on dialectics to become Dialectical Materialism, have all played a key role in the past century, and have remained ever-more relevant throughout.
He didn't always rock his famous beard, when he was younger he was clean shaven!
Some significant works:
Economic & Philosophic Manuscripts of 1844
The Eighteenth Brumaire of Louis Bonaparte
Critique of the Gotha Programme
Manifesto of the Communist Party (along with Engels)
And, of course, Capital Vol I-III
Interested in Marxism-Leninism, but don't know where to start? Check out my "Read Theory, Darn it!" introductory reading list!
I'm just saying that, one of the oldest known written texts, waaay before than when the old testament was written, is a customer complaint where they mention copper coins as currency. We don't know how common copper coins were, but saying that capital based societies are "young" is not correct either.
https://en.m.wikipedia.org/wiki/Complaint_tablet_to_Ea-n%C4%81%E1%B9%A3ir
Capital and money are not exactly the same thing. Capital is money used to make more money through (1) ownership of the means of production, (2) wage labor, and (3) economic rent & fincancialization.
Currency isn't Capitalism, though. Capitalism has currency, but not all systems with currency are Capitalist.