English-born Surveyor-General of Queensland, Australia, A. C. Gregory (1819-1905) made significant discoveries of land suitable for grazing in Western Australia, Queensland and in the Northern Territory. Gregory came to Australia at the age of ten and in 1841 became a cadet in the Surveyor-General's Department of Western Australia.
Promoted to assistant surveyor, Gregory was selected as leader of an expedition to explore northern Australia. The expedition travelled from the Victoria River in the Northern Territory eastward across central Queensland to the coast, which he followed from the Flinders River (near Rockhampton) to Brisbane. His favourable reports on many of the areas he crossed influenced later settlement.
In 1858 he was sent in search of the lost explorer Ludwig Leichhardt and travelled west through Queensland to the Barcoo River before drought compelled him to head for Adelaide. Late in 1859 he returned to Queensland to survey and mark its border with New South Wales. In the same year he was appointed Surveyor-General of Queensland, a position he retained until 1879. In 1882 he was appointed to the Legislative Council of Queensland and in 1903 was knighted.