This lengthy article features information on a recently published book entitled, First Five Thousand Years of Debt, by David Graeber, an anthropologist and anarchist. Although I haven't had time to read all of the article, I have read some of the three interviews that Graeber had about his book with various people, and found them to be useful in elucidating Graeber's new findings about the historical origins of money and debt.
...the very principle of exchange emerged largely as an effect of violence—that the real origins of money are to be found in crime and recompense, war and slavery, honor, debt, and redemption. That, in turn, opens the way to starting...an actual history of the last five thousand years of debt and credit....