As a student of Levin Goldschmidt, the founder of modern commercial law, Max Weber established the origins of commercial partnerships in the legal practice of medieval Italian cities in his doctoral thesis of 1889. In this, Weber was influenced decisively by the late phase of the historical school of law. With this first work, he laid the foundations for his later works, for which he was to become famous as a political economist, a sociologist, an economic historian and a philosopher of science. This edition documents Weber's scientific beginnings and provides a contribution to the image of legal science at the end of the 19th century. In addition, the subject bibliography makes a direct connection to the history of commercial law, which had been neglected for a long time.