This document provides an overview of the evolution of international monetary systems and financial crises. It discusses the Bretton Woods system, the move to floating exchange rates in the 1970s, and crises under fluctuating rates. It then covers the creation of the euro and the 2007-2009 financial crisis. The crisis originated from securitization of mortgages and financial innovations, and came to a head in September 2008 with the collapse of Lehman Brothers, drying up credit markets.