As he moved from Paris to London, Marx managed to leave a trail of uncleaned rooms and even more untidy relationships in his wake.
Mark picks his way through the discarded Pot Noodle cartons and unexpected children to reveal the real Marx.
You'll discover why the state of Marx's flat caused consternation amongst those sent to spy on him, and get to watch him doing his grocery shopping.
Mark also explains what made Marx's theories so revolutionary and why Marx wasn't a Marxist.
And did we mention the affairs?
First broadcast: Tuesday 7 Oct 2003 on BBC Four