Murdoch, initially alarmed that Northcliffe's staff had obtained a copy of his private letter, soon became a friend of the newspaper tycoon. Although his letter, written from memory, contained many mistakes and exaggerations, the main points were supported by other evidence and Hamilton was relieved of command, the subsequent operation to evacuate the troops from Gallipoli in December being accomplished with perfect effectiveness. In 1917, while visiting the Western Front as an unofficial war correspondent, Murdoch attempted to conduct negotiations with Field Marshal Douglas Haig in support of the Australian government's policy of the Australian Imperial Force (A.I.F.) divisions to be brought together into a united Australian Corps. Although Murdoch pushed for the appointment of Major General Brudenell White as the new corps commander while denigrating Major General John Monash (who was of Jewish German ancestry), the latter was given command when the Australian Corps was formed in 1918. Along with official war correspondent Charles Bean, Murdoch continued to lobby for Monash's demotion by appealing directly to Australian Prime Minister Billy Hughes and misleading him into the belief that the A.I.F.'s senior officers were strongly opposed to Monash. When Hughes visited the front just before the Battle of Hamel intending to replace Monash, he first consulted the same senior officers and discovered that their support for their commander was strongly positive and that Monash's powers of planning and execution were excellent. The subsequent outcome of the Hamel assault closed the question of Monash's suitability but later in the same year Murdoch attempted again to convince Hughes that Monash should not control the repatriation of Australian troops. Murdoch remained in London, expanding the cable service, writing influential journalism—and helping his friend Billy Hughes on visits to England—until he was offered the post of chief editor at the "Melbourne Herald", which he took in January 1921. Arranging for the paper's general manager to be demoted, he began applying Lord Northcliffe's principles, with frequent advice from Northcliffe himself. As he had in London, he focused on political controversy, but he also made the "Herald" influential in other ways, through such devices as improved arts coverage, and celebrity contributions. When the proprietor of the "Sydney Sun" tried to break into the Melbourne market with the "Sun News-Pictorial" in 1922, Murdoch fought a long campaign which eventually resulted in the "Herald", its own circulation up by 50%, taking over the new tabloid in 1925. He acquired the nickname "Lord Southcliffe" and in 1928 became managing director of the company, by which time the "Sun" was on its way to becoming Australia's highest-selling newspaper.