What does oligarchy mean? In the third episode of "Timothy Snyder Speaks," historian and author Timothy Snyder explores the meaning of oligarchy, where it came from, how it endangers us — and how it connects the United States and Russia.

Timothy Snyder is a historian at Yale University, specializing in eastern Europe, totalitarianism, and the Holocaust. His books have received widespread acclaim. His most recent book, "On Tyranny: Twenty Lessons from the Twentieth Century," explores the everyday ways a citizen can resist the authoritarianism of today. He is also the author of "Black Earth: The Holocaust as History and Warning" and, forthcoming in April, "The Road to Unfreedom: Russia, Europe, America."

Follow on Twitter: @TimothyDSnyder