Alexander von Humboldt, in full Friedrich Wilhelm Heinrich Alexander, Freiherr (baron) von Humboldt, (born September 14, 1769, Berlin, Prussia [now in Germany]—died May 6, 1859, Berlin), German naturalist and explorer who was a major figure in the classical period of physical geography and biogeography—areas of science now included in the Earth sciences and ecology. With his book Kosmos he made a valuable contribution to the popularization of science. The Humboldt Current off the west coast of South America was named after him. Von Humboldt is the patron scientist of the School of Natural Resources