Ambassador Hannah, born in 1939, was educated in Malaysia, New Zealand and at Cambridge University (MA in Economics). He joined the New Zealand Foreign Service in 1962.

Assignments in Wellington have included the Directorship of the European and Management Services Divisions, secondments to Treasury, the Department of Trade and Industry, and to the National Development Council.

Overseas, he has served in Paris, Brussels and Bangkok, and was Deputy Permanent Representative to the United Nations in New York, Permanent Representative to the United Nations in Geneva, and High Commissioner in Papua New Guinea, Singapore and Malaysia.