The Institutes of Gaius are the oldest (2nd century AD) textbook on Roman law, the most popular not only in antiquity, but also in our time. All serious novelists are still convinced today that the Institutes are the optimal textbook for students, since they have both the necessary brevity of presentation and a sufficiently deep immersion in the subject of Roman law of the classical period. At the same time, this book presents a variety of information not only on law, but also on the history of law (especially lawsuits) and religion, describes some very interesting rituals of antiquity, etc. In addition to the translation by F. Dydynsky, new fragments from Guy are included (translation by L.L. Kofanov).