| Adrian John Mardell | Director | 1 Jun 2019 | 30 Jun 2023 | British | 64 years |
| Bibiana Boerio | Director | 9 Sept 2004 | 15 Oct 2007 | American | 71 years |
| Bibiana Boerio | Director | 31 Jul 1995 | 1 Oct 2000 | United States | 71 years |
| Charles Gilbert Vacy Ash | Secretary | 24 Oct 2002 | 8 Feb 2006 | British | - |
| Charles Stephen Woolard | Director | 1 Oct 2000 | 31 Dec 2001 | Usa | 72 years |
| Clive Charles Page | Secretary | 19 Dec 1994 | 2 Jun 2008 | British | - |
| David Arthur Perry | Secretary | 4 Sept 1992 | 19 Dec 1994 | British | - |
| David Miles Smith | Director | 1 Jan 2002 | 18 Nov 2005 | British | 64 years |
| David Miles Smith | Director | 7 Mar 2008 | 8 Feb 2010 | British | 64 years |
| Frank Lazzaro | Director | 18 Nov 2005 | 7 Mar 2008 | Australian | 65 years |
| Helen Mary Mclintock | Secretary | 8 Feb 2006 | 27 Nov 2006 | British | - |
| Helen Mary Mclintock | Secretary | 30 May 2008 | 15 Aug 2008 | British | - |
| John Frederick Edwards | Director | 28 Sept 1991 | 31 Jul 1995 | British | 77 years |
| Jonathan Edward Osgood | Secretary | 13 Jul 2005 | 30 Jun 2008 | British | - |
| Keith John Benjamin | Director | 31 Mar 2011 | 22 Sept 2022 | British | 69 years |
| Kenneth David Matheson Gregor | Director | 10 Jun 2008 | 1 Jun 2019 | British | 58 years |
| Michael Charles Stewart Edwards | Secretary | 24 Oct 2002 | 28 Oct 2011 | Other | - |
| Michael David Wright | Director | 25 Feb 2004 | 9 Sept 2004 | British | 72 years |
| Michael Francis Marecki | Secretary | 24 Oct 2002 | 30 Jun 2005 | British | - |
| Michael Patrick O'driscoll | Director | 1 Aug 2007 | 31 Mar 2011 | British | 69 years |
| Richard Martin Alistair Bielby | Secretary | 15 Oct 2007 | 21 Sept 2018 | Other | - |
| Robert Murray Grant | Secretary | 28 Sept 1991 | 30 Sept 1991 | British | - |
| Roger George Putnam | Director | 28 Sept 1991 | 28 Feb 2002 | British | 80 years |
| Stephen John Perrin | Director | 1 Mar 2002 | 25 Feb 2004 | British | 78 years |
| Susan Lesley Pearson | Secretary | 26 Feb 1999 | 31 Mar 2019 | Other | - |