| Alison Erica Macdonald | Secretary | 25 Jun 1996 | 31 May 2005 | British | - |
| Anthony John Burnet | Director | 14 Jul 1989 | 11 Mar 2006 | British | 80 years |
| David William Alexander Macdonald | Director | 14 Jul 1989 | 11 Jul 1998 | British | 92 years |
| Geoffrey Keggen Maddrell | Director | 22 Feb 1995 | 30 Oct 2002 | British | 90 years |
| Gerard Vincent Welch | Director | 2 Dec 1996 | 30 Apr 1998 | British | 68 years |
| Guillaume Marie Maurice Penot | Director | 30 Jul 2008 | 15 Jul 2014 | French | 63 years |
| Hugues Michel Pietrini | Director | 1 Sept 2014 | 2 Feb 2017 | French | 57 years |
| Iain Lindsay Hamilton | Director | 6 Jan 1997 | 14 Aug 2009 | British | 71 years |
| Ian Maxwell Drysdale | Director | 25 Oct 1994 | 31 Dec 2015 | British | 70 years |
| Ian Robert Buxton | Director | 14 Jul 1989 | 31 Dec 1990 | British | 73 years |
| James Hood Fyfe | Director | 14 Jul 1989 | 18 Oct 1996 | British | 85 years |
| Jean-marc Francois Nicolas Gallot | Director | 1 Mar 2014 | 1 Sept 2014 | French | 62 years |
| Jean-marc Rene Boulan | Director | 30 Apr 2017 | 1 Jul 2022 | French | 54 years |
| Keith Graeme Edelman | Director | 16 May 2002 | 18 Jan 2005 | British | 76 years |
| Keith Lindsay Steel | Director | 14 Jul 1989 | 1 Apr 1996 | British | 82 years |
| Malcolm Angus Todd | Director | 24 Sept 1990 | 16 Jun 1995 | British | 70 years |
| Marc Hoellinger | Director | 31 Jan 2014 | 15 Aug 2018 | French | 57 years |
| Martha Jayne Fleming | Secretary | 1 Jun 2005 | 30 Apr 2017 | British | - |
| Martha Jayne Fleming | Director | 14 Aug 2009 | 30 Apr 2017 | British | 59 years |
| Nauman Saleem Hasan | Director | 1 Sept 2016 | 1 Oct 2022 | British | 57 years |
| Neil Alexander Herdman Mckerrow | Director | 14 Jul 1989 | 29 Jun 1994 | British | 81 years |
| Paul Anthony Neep | Director | 10 Feb 1997 | 12 May 2015 | British | 73 years |
| Paul Henry Skipworth | Director | 1 Apr 2009 | 31 Jan 2014 | Zimbabwean | 58 years |
| Peter Beszant Cullen | Director | 14 Jul 1989 | 31 Aug 1996 | British | 89 years |
| Peter Beszant Cullen | Secretary | 14 Jul 1989 | 25 Jun 1996 | British | - |
| Peter Jonathon Nelson | Director | 16 Jan 2001 | 1 Apr 2025 | British | 67 years |
| Peter Michael Arvor Darbyshire | Director | 20 Apr 1995 | 6 Jul 1998 | British | 76 years |
| Richard Spencer Yeomans | Director | 30 Apr 2017 | 1 Jan 2021 | British | 47 years |
| Simon David Erlanger | Director | 1 Apr 1994 | 1 Jan 2003 | British | 67 years |
| Thomas Jean Moradpour | Director | 15 Aug 2018 | 3 Jul 2023 | French | 53 years |
| William Bennett Brown | Director | 14 Jul 1989 | 19 Feb 1996 | British | 90 years |