Ranke was a professor at the University of Berlin. He was a professor there for almost 50 years. While there he criticized the historical theories of Georg Wilhelm Friedrich Hegel. He also advised his students to go to archives in search of sources. Because of this many think of him as the founder of a historical social science. Ranke retired as a professor in 1871, but still wrote history. In 1880 he started writing a book on world history, beginning in Ancient Egypt with the story of the Israelites. When he died in 1886 he had not finished his book, and had only written up to the 12th century. 