Copper was discovered here by Francis Galton in 1851 and being exploited after 1900. Attained municipal status in 1965. The name is said to be derived from Herero ‘osume’, (algae) which the green oxidised copper ore resembles. Or a Khoikhoi adaption of Herero and to mean ‘place of frogs’ or ‘evil place’ because malaria was rife there in former times.