Mr. Leslie was born in 1921 and graduated from the School of Forestry, Creswick, Victoria, Australia in 1941. He spent a period in the Second World War in active service in submarines in the Pacific theatre and was wounded whilst gunnery officer during an air attack on his vessel. He then served with the Forests Commission and APM Forests Pty. Ltd. before being appointed Lecturer in Forest Management at the University of Melbourne in 1958. He was promoted to Senior Lecturer in 1962 and graduated to a Master of Science in Forestry in 1963. He taught at the University of Ibadan from 1962-64 and was Reader at the School of Forestry, University of Canterbury, from 1974-77. He served with the Food and Agricultural Organisation of the United Nations for various periods, rising to become Director of the Forest Industries Division at the time of his so-called retirement in 1981. He is a Fellow of the Institute of Foresters of Australia and past President of the International Union of Societies of Foresters. He has continued to be active in consultancy work in many developing countries and has contributed greatly to the standing of Australian forestry throughout the world.