From the Middle Ages until the Age of Enlightenment, scholars sought various forms of noble and religious patronage or funded their own work through medical practice. In the 18th and 19th centuries, many disciplines began to professionalize, and both government-sponsored "prizes" and the first research professorships at universities drove scientific investigation. In the 20th century, a variety of sources, including government organizations, military funding, patent profits, corporate sponsorship, and private philanthropies, have shaped scientific research.