In their own words

… it was an idea which largely matured during my first sojourn in the far South. At times, during the long hours of steady tramping across the trackless snow-fields, one’s thoughts flow in a clear and limpid stream … It may have been in one such phase that I suddenly found myself eager for more than a glimpse of the great span of Antarctic coast lying nearest to Australia … The limiting outposts had been defined by other expeditions; at Cape Adare on the east and at Gaussberg on the west. Between them lay my ‘Land of Hope and Glory,’ of whose outline and glacial features the barest evidence had been furnished …

The idea of exploring this unknown coast took firm root in my mind while I was on a visit to Europe in February 1910. The prospects of an expedition operating to the west of Cape Adare were discussed with the late Captain RF Scott … Sir Ernest Shackleton was warmly enthusiastic when the scheme was laid before him, hoping for a time to identify himself with the undertaking …

For many reasons, besides the fact that it was the country of my home and Alma Mater, I was desirous that the Expedition should be maintained by Australia. It seemed to me that here was an opportunity to prove that the young men of a young country could rise to those traditions which have made the history of British Polar exploration one of triumphant endeavour as well as of tragic sacrifice. And so I was privileged to rally the ‘sons of the younger son.’

— Douglas Mawson, The Home of the Blizzard