German cavalryman and naturalist from Kustrin. He served in the Prussian Campaign during the Napoleonic wars and was awarded the Iron Cross. He studied medicine at Berlin and his abilities impressed M.H.K. von Lichtenstein, who became his patron and recommended him to the company of Pallas and Poleman at the Cape where he was subsequently employed (1815-1817). Bergius collected South African natural history material in his free time and sent it to the Berlin Museum. During this period he met a number of naturalists at the Cape and travelled with them during local field collecting, though he is not acknowledged as a co-collector. He also assisted J.L.L. Mund and L. Maire when they arrived at the Cape on an official collecting expedition for the Berlin Museum, though he was disappointed not to be selected for the expedition himself.

He left the employment of Pallas and Poleman, where he found his treatment to be unacceptable, but his freedom to collect was quickly brought to an end when he developed tuberculosis. Still a young man but abandoned by his former employers, colleagues and patron, he died in poverty on 4 January 1818. In April of the same year a friend from Berlin, von L.K.A. von Chamisso, called on him only to find that the promising naturalist had already died. He forwarded the manuscripts and collections of Bergius to Berlin, where a number of botanists posthumously honoured him with plant names. He is commemorated by Diascia bergiana Link & Otto, Ficinia bergiana Kunth and Ophioglossum bergianum Schltdl.