This striking variation from the common fate of peoples is attributable to three causes. First, the development of a British civilisation in Australia has synchronised with the attainment and unimpaired maintenance of dominant sea-power by the parent nation. The supremacy of Great Britain upon the blue water enabled her colonies to grow to strength and wealth under the protection of a mighty arm. Secondly, during the same period a great change in British colonial policy was inaugurated. Statesmen were slow to learn the lessons taught in so trenchant a fashion by the revolt of the American colonies; but more liberal views gradually ripened, and Lord Durham's Report on the State of Canada, issued in 1839, occasioned a beneficent new era of self-government. The states of Australia were soon left with no grievance which it was not within their own power to remedy if they chose, and virtually as they chose. Thirdly, these very powers of self-government developed in the people a signal capacity for governing and being governed. The constitutional machinery submitted the Executive to popular control, and made it quickly sensitive to the public will. Authority and subjects were in sympathy, because the subjects created the authority. Further, there was no warlike native race in Australia, as there was in New Zealand and in South Africa, to necessitate armed conflict. Thus security from attack, chartered autonomy, and governing capacity, with the absence of organised pugnacious tribes, have combined to achieve the unique result of a continent preserved from aggression, disruption, or bloody strife for over one hundred and twenty years. There was a brief period, as will presently be related, when this happy state of things was in some danger of being disturbed. It certainly would have been impossible had not Great Britain emerged victorious from her protracted struggle, first against revolutionary France, and later against Napoleon, in the latter years of the eighteenth century and the beginning of the nineteenth.