| Alfred Michael Heath | Director | 14 May 1997 | 5 Oct 1998 | British | 89 years |
| Andrew Charles Cunninghame Farran | Director | 29 Nov 1994 | 27 Feb 1997 | Australian | 87 years |
| Andrew Charles Cunninghame Farran | Director | 14 May 1997 | 22 Jul 2003 | Australian | 87 years |
| Anne Coleman | Secretary | 26 Oct 2001 | 7 Apr 2004 | British | - |
| Anthony Christopher Pinder | Director | 31 Dec 1991 | 29 Nov 1994 | British | 85 years |
| Anthony Christopher Pinder | Director | 13 Jan 1997 | 27 Feb 1997 | British | 85 years |
| Anthony Christopher Pinder | Director | 14 May 1997 | 3 Jun 2019 | British | 85 years |
| Bernard Barron Silverstone | Director | 28 Jul 2004 | 23 Nov 2010 | British | 70 years |
| Bijan Fouladgar | Director | 21 Oct 1992 | 14 May 1997 | British | 85 years |
| Brian Charles Clancy | Director | 20 Sept 2012 | 27 Sept 2023 | British | 77 years |
| Charles Henry Bruggmann | Director | 29 Nov 1994 | 14 May 1997 | Swiss | 98 years |
| Colin James Hood | Director | 28 Jul 2004 | 25 Jul 2006 | British | 84 years |
| David Edward Simmonds | Director | 28 Sept 2017 | 3 Sept 2019 | British | 73 years |
| Donald Macleod Forbes | Director | 31 Dec 1991 | 14 May 1997 | British | 85 years |
| Donald Macleod Forbes | Secretary | 31 Dec 1991 | 16 May 1997 | British | - |
| Geoffrey Forman | Director | 15 Jul 1996 | 23 Dec 1996 | British | 91 years |
| Gordon Bryan Coates | Director | 29 Nov 1994 | 14 Oct 1996 | British | 91 years |
| Hayley Louise Rigby | Director | 1 Jan 2022 | 25 Jul 2024 | British | 34 years |
| James Peyton Robinson | Director | 9 Sept 1997 | 30 Jul 2002 | British | 72 years |
| John Neil Keary | Director | 26 Sept 2017 | 6 Dec 2024 | British | 83 years |
| Margaret Ann Imfeld Morris | Director | 28 Jul 2004 | 20 Sept 2012 | British | 76 years |
| Margaret Ann Imfeld Morris | Director | 30 Sept 2015 | 15 Apr 2023 | British | 76 years |
| Margaret Elizabeth Forman | Director | 20 Sept 2012 | 17 May 2016 | British | 82 years |
| Margaret Pollock | Director | 2 Oct 2008 | 3 Sept 2019 | British | 91 years |
| Michael Narramore Peterson | Director | 31 Dec 1991 | 29 Nov 1994 | British | 87 years |
| Nicholas David Padfield Kc | Director | 2 Mar 2020 | 6 Dec 2024 | British | 78 years |
| Peter Joseph Albert Marsh | Director | 14 May 1997 | 6 Jul 2023 | British | 86 years |
| Peter Joseph Albert Marsh | Secretary | 16 May 1997 | 26 Oct 2001 | British | - |
| Robert Nicholas Drysdale Allen | Director | 14 May 1997 | 2 Oct 2008 | British | 76 years |