“In terms of time, my work will start with the 140th Olympiad” wrote the historian Polybius at the beginning of his History: 
Before this time things happened in the world pretty much in a sporadic fashion, because every incident was specific, from start to finish, to the part of the world where I happened. But ever since then history has resembled a body, in the sense that incidents in Italy and Libya and Asia and Greece are all interconnected, and everything tends toward a single outcome. That is why I have made this period the starting point of my treatment of world events.
With me to discuss the historian Polybius and his work is Steele Brand. He is Professor of History at The King’s College in New York, and author of Killing for the Republic: Citizen-Soldiers and the Roman Way of War, which he and I discussed in Episode 124.

For Further Investigation
Arthur Eckstein, Moral Vision in the Histories of Polybius 
Frank W. Walbank, A Historical Commentary on Polybius  
Brian C. McGing, Polybius' Histories 
Bruce Gibson and Thomas Harrison, eds., Polybius and His World: Essays in Memory of F.W. Walbank
Polybius, translated by Robin Waterfield, The Histories 

Episode 45: The View from Thucydides' Tower
Episode 11: The First Historian