Ratzel, Friedrich (frēˈdrĭkh rätˈsəl) [key], 1844–1904, German geographer. He traveled as a journalist in Europe (1869) and in Cuba, Mexico, and the United States (1872–75). Thereafter he devoted himself to geographical studies and taught geography at the polytechnical school in Munich (1876–86) and at the Univ. of Leipzig (from 1886). He was a pioneer in developing the school of anthropogeography and was the founder of modern political geography. He emphasized the importance of physical environment as a factor determining human activity. His geographic concepts had a profound influence on European and American geographers and he had many followers. The most noted of his many works are Anthropogeographie (2 vol., 1882–91) and Politische Geographie (1897).