The Australian Antarctic Territory (AAT) is a part of Antarctica. It was claimed by the United Kingdom and placed under the authority of the Commonwealth of Australia in 1933. It is the largest territory of Antarctica claimed by any nation. In 1961, the Antarctic Treaty came into force. Article 4 deals with territorial claims, and although it does not renounce or diminish any preexisting claims to sovereignty, it also does not prejudice the position of Contracting Parties in their recognition or non-recognition of territorial sovereignty.