On 31 October 1517 an obscure German monk named Martin Luther posted 95 theses protesting the selling of indulgences. This single act brought him into inevitable conflict with both pope and emperor. The dispute that followed changed not only Luther's life, but also the religious and political face of Europe. This book offers the modern reader a concise and accessible account of Luther's remarkable life. It explores his passionate and fiery character, introduces us to a colourful cast of friends and enemies, and explains the complex politics of church and empire. Whether you agree or disagree with Luther, you will be left with little doubt that his life and thought have shaped the world in which we live - and in more ways than you may have thought.