Born in Brisbane. Cadet at Courier-Mail. Joined Communist Party of Australia in 1939. Enlisted in Australian Army in 1941 and served as lieutenant in New Guinea then as a pilot in the Australian Air Force. Returning to Courier-Mail after the war, he was awarded the Kemsley Empire Journalism Scholarship, reporting from London and Europe. Fired by Keith Murdoch for not obeying editorial instructions. Robertson then become sub-editor of the Melbourne Argus, before joining the Victorian Peace Council. He became secretary of the NSW Peace Council in 1951. Robertson married Mavis Moten in 1953. In the 1950s Robertson was elected to the CPA's Central Committee and later the National Committee. Became Chief Editor of the Tribune in 1964. Campaigned for Papua New Guinea's independence and the anti-Vietnam war movement, and other left wing causes.