The Sir Douglas Mawson Collection comprises two letters and a canister. The first letter, dated 5 January 1931, is a proclamation hand-written in copperplate on rag paper by A L Kennedy, a physicist in Mawson's party, and signed by Sir Douglas Mawson, proclaiming British sovereignty over King George V Land (Antarctica) between Longitudes 142 and 160 degrees east of Greenwich, and between Latitude 66 degrees south and the South Pole. The second is a transcript of a later proclamation signed by Mawson on 18 February, 1931 stating: "proclamation read and flag planted on McRobertson Land " Latitude 67.26 South, Longitude 60.49 East claiming large tracts of Antarctica Mainland and off lying islands. The collection also contains a metal canister made from three food tins soldered together. It was in this canister that Mawson placed the 5 January 1931 proclamation at Cape Denison. Forty-six years later, members of the 1977 Australian Antarctic Expedition retrieved the objects from their burial place beneath a cairn in Commonwealth Bay.
Distinguished polar explorer and scientist, Sir Douglas Mawson (1882-1958), led three research expeditions to Antarctica, the first from 1911-14, and the second and third - British, Australian and New Zealand Antarctic Research Expeditions (BANZARE) - in 1929-30 and 1930-31. However, as well as the advancement of scientific exploration, oceanographic work and biological knowledge, great emphasis for Mawson's later voyages lay on British intentions to pre-empt territorial expansion by Norway, which was intent on securing rights over Antarctic territory to support and extend its whaling industry. Instructions issued by Prime Minister Robert Bruce to Mawson on 12 September 1929, explained clearly that territorial acquisition (in Bruce's words, to "plant the British flag") was to be a chief objective of his voyages. The documents in this collection are considerably important in terms of territorial claims and international politics. Mawson's team were the first to map much of the coast, and this provided firm foundation for sovereignty over 5,800,000 square kilometres, or forty-two percent, of eastern Antarctic Territory to be transferred from Britain to Australia under the Australian Antarctic Territory Acceptance Act 1933, which came into effect in 1936. Although several states have claimed territory in Antarctica, Australia effectively controls a greater area than has been claimed by any other nation.