On Halloween 1517, Martin Luther nailed to the door of Wittenberg’s Castle Church his 95 Theses protesting papal indulgences. It is one of the ironies of history that at the very moment when Charles V came to rule over a European empire which was, for the first time, as large as that controlled by Charlemagne, a young Saxon monk irrevocably shattered its very raison d’Òetre. Luther’s solitary stand against the Pope and the Holy Roman Emperor at the Diet of Worms in 1521, and his magnificent German translation of the Bible in the 1530s secured his place in history as one of the greatest religious thinkers of all time. His vast oeuvre (over 70 volumes) sprang from one idea — that believers are saved by faith alone and not works — and incited the world’s biggest evangelical revival, provoking the re-thinking of deep-seated ideas about church and state, government and the individual, war and peace.