Born at Königsberg, East Prussia (now Kaliningrad, Russia), Gustavus Ferdinand von Tempsky came from a military family whose traditions he followed by attending cadet schools in Potsdam and Berlin. In 1846, he left Prussia for the Mosquito Coast (now Nicaragua), moving on to California by 1850, where he failed to make a fortune as a goldminer. By 1857 he was living in Scotland, his wife’s birthplace, and in 1858 he travelled to Australia, again in search of gold.
News of gold mining prospects on the Coromandel brought von Tempsky, his wife and three children to Tāmaki Makaurau on 10 March 1862. On 24 August 1863, he took out British citizenship to allow him to obtain a commission with the Forest Rangers. He saw action during the Waikato War, establishing a reputation as an intrepid leader. Although ruthless in pursuit of fighting Māori, he disapproved of the killing of the women, children, and wounded, as had occurred at Ōrākau.
A more extensive biography is available on Te Ara The Encyclopedia of New Zealand.