South Australia. The absence of any legal title meant that these intruders became known as 'squatters' and the terms of their tenure were not finally settled until 1846 after a prolonged political struggle with the Governor of New South Wales, Sir George Gipps. The impact of the original penal settlements on the indigenous population had been enormous. The consequences of squatting after 1820 were equally devastating as the land and natural resources upon which indigenous hunter-gathering activities and environmental management depended were appropriated on a massive scale. Aboriginal populations collapsed in the face of disease, violence and forced removal until they survived only on the margins of the new pastoral economy, on government reserves, or in the arid parts of the continent least touched by white settlement. The process would be repeated in northern Australia during the second half of the century. Colonial governments and settlers did not recognise any Aboriginal land rights or sovereignty (arguable under the doctrine of terra nullius) and therefore felt free to expand into their territory with impunity. The encouragement of private enterprise, the reception of Wakefieldian ideas, and the wholesale spread of white settlement were all part of a profound transformation in official and private perceptions of Australia's prospects and economic value as a British colony. Millennia of fire-stick management to assist hunter-gathering had created inland grasslands in the southeast that were ideally suited to the production of fine wool. Both the physical environment and the official incentives just described raised expectations of considerable profits to be made in pastoral enterprise and attracted a growing stream of British capital in the form of organizations like the Australian Agricultural Company (1824), which was granted the right to select 1,000,000 acres (4,047 km2) in New South Wales for agricultural development; and new corporate settlements were established in Western Australia (1829) and South Australia (1836). By the 1830s, wool had overtaken whale oil as the colony's most important export, and by 1850 New South Wales had displaced Germany as the main overseas supplier to British industry. Allowing for the colonial economy's growing complexity, the cycle of growth based upon land settlement, exports and British capital would be repeated twice. The first pastoral boom ended in a depression which was at its worst during 1842–43. Although output continued to grow during the 1840s, the best land had been occupied in the absence of substantial investment in fencing and