To many Europeans, perhaps to a great many, Islam is something of a puzzle. In the news media and on the Internet they witness scenes of great piety during the hajj in Mecca, but also witness scenes of great barbarity in that same holy city itself and in other great cities and the deserts of Islam. They can experience the glorious and highly sophisticated architectural, horticultural and culinary delights of Moorish Spain, but are then faced with evidence of corruption, depravity, and terrible slaughter within and by the Muslim communities in their own cities. And now, in the 21st century fear and hatred have returned to the streets in the cities of Europe. Modern Europeans are themselves experiencing that hate and those fears that once stalked the pages of their mediaeval history. And they ask why? This book seeks to understand Islam. Not to defeat it, but to answer the question - why? Is there anything in this religion that encourages the use of the barbaric violence that we are now witnessing in its name? Its conclusions may anger some, and irritate others, but they should surprise no one.