Few medical or scientific addresses have so unmistakeably made history as the presentation delivered by Alois Alzheimer on November 4th, 1906 in Tübingen. The celebratory event, "Alzheimer 100 Years and Beyond" organized on the initiative of the Alzheimer community in Germany and worldwide, in collaboration with the Fondation Ipsen, at the very site of the original lecture, namely the Institute of Psychiatry at the University of Tübingen in Germany from November 2nd to 5th, 2006, was the highlight of the Alzheimer Year. Over the last century of Alzheimer research (1906-2006), remarkable progress has been achieved. Most of the authors of the major discoveries and the people involved in research in this field will present, during the meeting and in this volume, the pioneering research explaining the conditions under which they were conducted. The goal of this book is to honor the work accomplished, to summarize the most important knowledge and to provide material for the history of science.