German civil law with its central codification in the BGB [German Civil Code], which is more than one hundred years old, suffers from a lack of systematic unity even after the modernization of contract law. This makes it harder for students and trainee teachers in education, judges and attorneys in practise, teachers and researchers in science, and not least the lawyers of our European neighbors, to gain or keep the overview of the main basis and the various connecting lines of the individual legal institutes and aspects of the German civil law. A compendium is necessary, which provides a comprehensive overview of the most important fields of law and offers a supportive reference framework, to help practical positioning of the standards and decisions of the legal figures and institutes. The newly developed concept of the Staudinger volume “cornerstone of the civil law” strives for such a compendium. Based on an “introduction to the BGB [German Civil Code]” – connected to the sequence in the BGB, supplemented by cross-referenced contributions – more than twenty topics are presented and described, such as “the legal transaction”, “establishing obligations”, “defaults”, “legally securing a loan”, “types of contract”, “rent”, “the works contract”, “unfair expansion and non-contracted management”, “the real estate law” etc. The authors are primarily very experienced university lecturers. Readers who want information on a specific topic or an overview of a regulation will be just as well informed with the “cornerstone of the civil law” as the reader of the complete works in their search for deep meaning and background to the civil law.