The son of a judge, Christian Gottfried Ehrenberg was born in Delitzsch, near Leipzig. He first studied theology, then medicine and natural sciences in Berlin and became a friend of the famous explorer Alexander von Humboldt. In 1818, he completed his doctoral dissertation on fungi, Sylvae mycologicae Berolinenses. In 1820-1825, on a scientific expedition to the mid-east, he collected thousands of specimens of plants and animals. After his return, he published several papers on insects on corals, and he began to concentrate his studies on microscopic organisms, which until then had not been systematically studied. For nearly 30 years Ehrenberg examined samples of water, soil, sediment, and rock and described thousands of new species, among them many teeny fossils, in nearly 400 scientific publications. He was particularly interested in a unicellular group of protists called diatoms, but he also studied, and named, many species of radiolarians.
Ehrenberg was appointed professor of medicine at Berlin University in 1839, and foreign member of the Royal Society of London in 1837. After his death in 1876, his collections of microscopic organisms were deposited in the Museum für Naturkunde at the Humboldt-Universität, Berlin. The "Ehrenberg Collection" includes 40,000 microscope preparations, 5,000 raw samples, 3,000 pencil and ink drawings, and nearly 1,000 letters of correspondence.