The geographer, naturalist, and explorer Alexander von Humboldt (1769–1859) in his library at Oranienburger Straße 67 in Berlin. Shaped by the educational ideals of German classicism, Humboldt embarked on a five-year expedition to Latin America in 1799 in order to conduct detailed field research. Humboldt's extensive library suggests the wide range of his interests and knowledge. He was the younger brother of Wilhelm von Humboldt (1767–1835), a renowned philosopher, scholar, linguist, and politician, and the founder of the University of Berlin. Lithograph after a watercolor by Eduard Hildebrandt.