Greek city states chose as their ambassadors the finest orators, the most plausible advocates, who were required to plead the cause of their cities before the popular assemblies of foreign leagues or cities. Their most important task was to deliver a magnificent speech. Much more is expected of a modern envoy.

James Plimsoll was a great Australian ambassador, one of the finest of his generation. An extraordinary capacity to secure the trust and confidence of foreign leaders and of his own government, high intellect, hard work, prolific reading, selflessness and modesty distinguished Plimsoll. He could also make a magnificent speech. Sir Paul Hasluck, former governor-general and foreign minister, wrote "because of Plimsoll, there are quite a number of highly placed foreigners who think of Australians as persons of intelligence, understanding, courtesy, consideration and a good intention".

Appointed ambassador on eight separate occasions, by Menzies, Gorton, Whitlam and Fraser, his assignments comprised the United States, USSR, India, the European Community, Britain, Japan, Korea and the United Nations. Plimsoll was part of a generation led by Tange and Crawford, and including Waller, Shaw, Edwin McCarthy and Westerman, who strengthened substantially the foundations of Australian foreign and trade policy.

At age 33, and only three years after joining the Department of External Affairs, Plimsoll was appointed by Menzies as ambassador and Australian representative to the United Nations Committee for the Unification and Rehabilitation of Korea (UNCURK). Other names considered were former NSW Premier Sir Bertram Stevens and L. J. Hartnett of General Motors Holden. Plimsoll quickly became the most influential member of UNCURK and a major influence on Korean President Syngman Rhee.  UNCURK did not reunify Korea but it provided necessary stability to the south, ensured some respect for constitutional government, and helped prevent Rhee liquidating the opposition. It was a young Plimsoll who had to tell Rhee that he had to accept a settlement based on a divided Korea. On one celebrated occasion Rhee went to the airport intending to flee his country. Upon hearing this, Plimsoll, clad only in his pyjamas, pursued him to the airport and persuaded him to remain. The youthful ambassador's work in Korea drew high praise from US Secretary of State, Dean Acheson, and built Plimsoll's reputation among Australia's political leaders.

After education at Sydney Boys High School, and an economics degree from Sydney University, Plimsoll joined the Bank of New South Wales as a research economist. He joined the militia when war broke out and subsequently joined the army as a captain. Within a very short time he was invited by an older friend from university, Alf Conlon, to join the Army's Directorate of Research. In one of the army's most audacious initiatives Conlon was allowed to recruit some of Australia's finest young minds to work on political and economic issues relevant to the war effort and beyond. This eclectic group at various stages included anthropologist Bill Stanner, poets James McAuley and Harold Stewart, Eric Willis later NSW Premier, lawyer Julius Stone, writer Donald Horne and many others. Arising from Conlon's support Plimsoll worked on Papua New Guinea and Japan, spent three years in Washington with the US military, and became the de facto Australian representative on the Far Eastern Commission set up by the Potsdam agreement. While disagreeing with his politics, Plimsoll became a close adviser to External Affairs Minister Evatt and travelled with him often. Evatt persuaded Major Plimsoll to join External Affairs at age 30.

Plimsoll subsequently became close to Menzies and delighted him with his work as ambassador to the United Nations and subsequently as high commissioner to India. Plimsoll was reluctant to accept Menzies' request to be Secretary of External Affairs; he preferred to continue his work in India. Plimsoll's forebodings were borne out. He was a poor administrator. He also failed to ensure opportunities for women diplomats. Plimsoll's strength was as an envoy and Gorton made him ambassador to the United States. There he rendered important service to Whitlam when three of his ministers publicly said of President Nixon's Administration there were "thugs" and "maniacs" in the White House.

Plimsoll never got on with Malcolm Fraser, who treated him badly in London to the dismay of British ministers, and who had reservations, understandably, about Plimsoll's advice to Whitlam in favour of de jure recognition of Soviet sovereignty of Estonia, Latvia and Lithuania. Plimsoll's greatest problem with the Fraser government came when his advice about policy towards the EEC was not accepted by Fraser or his Minister for Special Trade Negotiations, John Howard. Plimsoll, uncharacteristically, was not well informed about the Fraser government's serious objections to Europe dumping subsidised agricultural products in markets developed by Australia. Fraser correctly assessed that Plimsoll's view that the UK as a new member would help look after Australia's agricultural interests would not be realised.

Plimsoll finished his career as a much loved and esteemed governor of Tasmania.

Hearder's book, well edited by John Nethercote, does justice to the outstanding career of a distinguished diplomat. A measure of Plimsoll's eminent international stature was provided on the 75th birthday of Jawaharlal Nehru. India's leaders invited notable world citizens to contribute to a book of essays. Plimsoll was the only Australian included with dual Nobel laureate Linus Pauling, Arnold Toynbee, J K Galbraith, Willy Brandt, Pierre Mendes-France, Gunnar Myrdal and Earl Mountbatten.

Philip Flood is a former secretary of the Department of Foreign Affairs and Trade.