| Allen John Lloyd | Director | 9 Dec 1993 | 23 Feb 1999 | British | 76 years |
| Allen John Lloyd | Director | 9 Dec 1999 | 8 Jun 2006 | British | 76 years |
| Andrew Lionel Nahum | Director | 30 Jul 1999 | 7 Jun 2001 | British | 80 years |
| Bibiana Boerio | Director | 2 Sept 2004 | 15 Oct 2007 | American | 71 years |
| Charles Henry Gordon Lennox | Director | 9 Sept 1999 | 5 May 2004 | British | 70 years |
| Daniel James Pink | Director | 23 Jan 2020 | 20 Oct 2022 | British | 40 years |
| David Alan Boole | Director | 24 Aug 1991 | 31 Jan 1996 | British | 78 years |
| David Arthur Perry | Director | 10 Jun 1999 | 30 Sept 2004 | British | 83 years |
| David Arthur Perry | Secretary | 4 Sept 1992 | 10 Jun 1999 | British | - |
| David Fielden | Director | 24 Aug 1991 | 30 Sept 1991 | British | 87 years |
| Derek Todd | Director | 11 Jun 2003 | 4 Dec 2008 | British | 66 years |
| Donald Anthony Hume | Director | 1 Mar 2007 | 4 Dec 2008 | British | 74 years |
| Ernest Ian Appleyard | Director | 24 Aug 1991 | 10 Sept 1993 | British | 102 years |
| Fiona Pargeter | Director | 8 Mar 2013 | 11 Apr 2019 | British | 56 years |
| Frank Henning Christian Klaas | Director | 11 Nov 2011 | 5 Jun 2014 | German | 67 years |
| Geoffrey William Cousins | Director | 2 Sept 2010 | 9 Oct 2013 | British | 69 years |
| Hanno Kirner | Director | 12 Jul 2018 | 31 Dec 2023 | German | 55 years |
| Ian Stuart Callum | Director | 6 Dec 2007 | 11 Apr 2019 | British | 71 years |
| John Connell O'donnell | Director | 4 Dec 2008 | 2 Jun 2010 | United States | 63 years |
| John Stirling Edwards | Director | 16 Jan 2014 | 30 Jun 2018 | British | 63 years |
| Jonathan Andrew Bryant | Director | 6 Dec 2001 | 8 May 2003 | British | 73 years |
| Joseph Greenwell | Director | 7 Mar 1996 | 4 Dec 2003 | British | 74 years |
| Julian Philip Thomson | Director | 10 Oct 2019 | 31 May 2021 | British | 64 years |
| Keith John Benjamin | Director | 12 Jul 2018 | 20 Oct 2023 | British | 69 years |
| Kenneth Michael Mcconomy | Director | 2 Jun 2010 | 16 Jul 2012 | British | 57 years |
| Kenneth Walter Tom Edwards | Director | 24 Aug 1991 | 22 Feb 1999 | British | 100 years |
| Michael David Wright | Director | 11 Jun 2003 | 2 Sept 2004 | British | 72 years |
| Michael Ernest Beasley | Director | 9 Sept 1999 | 11 Jun 2003 | British | 82 years |
| Michael Ernest Beasley | Director | 1 Dec 2005 | 3 Mar 2021 | British | 82 years |
| Michael Harrington Dale | Director | 4 Dec 1997 | 22 Jun 2001 | Us Citizen | 90 years |
| Michael James Limb | Director | 24 Aug 1991 | 15 Aug 1994 | British | 92 years |
| Michael James Mohan | Director | 6 Dec 2007 | 10 Oct 2011 | British | 59 years |
| Michael Patrick O'driscoll | Director | 4 Sept 2003 | 16 Feb 2017 | British | 69 years |
| Michael Van Der Sande | Director | 12 Jul 2018 | 31 Oct 2022 | Dutch | 60 years |
| Neil Anthony Johnson | Director | 15 Aug 1994 | 21 Jan 2000 | British | 76 years |
| Neil Cossons | Director | 24 Aug 1991 | 1 Jul 2000 | British | 86 years |
| Olwen Winifred Phillips | Secretary | 24 Aug 1991 | 24 Feb 1992 | British | - |
| Paul Jonathan Barritt | Director | 2 Feb 2023 | 4 Oct 2024 | British | 52 years |
| Peter Mitchell | Director | 24 Aug 1991 | 5 Mar 2015 | British | 90 years |
| Philip Hodgkinson | Director | 3 Jun 2004 | 15 Oct 2007 | British | 66 years |
| Richard Charles Osborne Shore | Director | 16 Jan 2014 | 5 Mar 2015 | British | 61 years |
| Robert Alan Dover | Director | 1 Oct 1991 | 10 Aug 2017 | British | 80 years |
| Roger George Putnam | Director | 24 Aug 1991 | 2 Sept 2010 | British | 80 years |
| Simon David Andrew Sproule | Director | 11 Dec 2001 | 4 Sept 2003 | British | 57 years |
| Stephen John Cox | Secretary | 25 Feb 1992 | 4 Sept 1992 | British | - |
| Susan Lesley Pearson | Secretary | 26 Mar 1999 | 10 Jun 1999 | Other | - |
| Susan Lesley Pearson | Secretary | 10 Jun 1999 | 31 Mar 2019 | Other | - |
| Thomas Pallister | Director | 3 Jun 2004 | 9 Oct 2013 | British | 74 years |
| Tim Hannig | Director | 14 Jan 2016 | 30 Jan 2019 | German | 47 years |