The Australian colonies had agreed to federate, to form the Commonwealth of Australia from 1 January 1901. Hopetoun's popularity in Victoria and his friendship with leading Australian politicians made him an obvious choice to be the first Governor-General of Australia. In his submission to Queen Victoria in July 1900, Secretary of State for the Colonies Joseph Chamberlain described Hopetoun as "exceptionally qualified to discharge the duties of this important position with ability and efficiency" and stated that he would be "heartily welcomed" in Australia. His strong ties with the Queen and with the incumbent British administration were also important to appointers in London. His appointment was approved by the Queen on 14 July 1900 and on 29 October letters patent were issued constituting the office and his own instructions. Hopetoun arrived in Sydney on 15 December, via India, where he had caught typhoid fever and his wife malaria. Already in poor health during the preceding years in England, the trip further diminished Hopetoun's capacities.