Leopold von Ranke (December 21, 1795 – May 23, 1886) was a German historian of the 19th century, and frequently considered one of the founders of modern source-based history. Ranke set the tone for much of later historical writing, introducing such ideas as reliance on primary sources (Empiricism), an emphasis on narrative history and especially international politics (Aussenpolitik) Ranke is also considered a founding father of Historism.