| Alan Sharp | Director | 20 Feb 1991 | 16 May 1994 | British | 81 years |
| Barbara Plucnar Jensen | Director | 3 Oct 2016 | 28 Feb 2019 | Danish | 55 years |
| Bruce Andrew Van Der Waag | Director | 13 May 2019 | 22 Oct 2021 | Dutch | 60 years |
| Christopher Ian Mclain | Director | 13 Oct 2008 | 11 Aug 2009 | British | 62 years |
| Christopher Ian Mclain | Director | 8 Nov 1994 | 18 Nov 1996 | British | 62 years |
| Colin Robert Tennent | Director | 8 Nov 1994 | 18 Nov 1996 | British | 62 years |
| Colin Robert Tennent | Director | 28 Mar 2002 | 3 Oct 2008 | British | 62 years |
| David Thomas Simons | Director | 28 Mar 2002 | 20 Oct 2008 | British | 74 years |
| David Thomas Simons | Secretary | 14 Sept 2004 | 20 Oct 2008 | British | - |
| Duncan Hall | Director | 21 Aug 2007 | 13 Oct 2008 | British | 58 years |
| Duncan Hall | Director | 11 Aug 2009 | 13 Dec 2010 | British | 58 years |
| Edward Charles Chandler | Director | 27 Nov 2008 | 5 Nov 2009 | British | 48 years |
| Edward Charles Chandler | Secretary | 27 Feb 2009 | 5 Nov 2009 | British | - |
| Franciscus Oswaldus Bosch | Director | 28 Mar 2002 | 29 Jul 2004 | British | 60 years |
| Garry Francois Caroline Verbeeck | Director | 14 Dec 2009 | 9 Jan 2013 | Belgium | 70 years |
| Gary John Kidd | Director | 20 Jan 2015 | 1 Sept 2016 | British | 62 years |
| George Lilley | Director | 1 May 1993 | 18 Nov 1996 | British | 67 years |
| Hans Juerg Bracher | Director | 20 Feb 1991 | 28 Feb 2002 | Swiss | 87 years |
| Ian Davidson | Director | 5 Oct 2009 | 20 Jan 2015 | British | 63 years |
| Ian Davidson | Secretary | 5 Nov 2009 | 20 Jan 2015 | - | - |
| Ian Scarr Hall | Director | 20 Feb 1991 | 30 Nov 2006 | British | 88 years |
| Jamie Reynolds | Director | 13 Oct 2008 | 16 Oct 2009 | British | 51 years |
| John Anthony Brian Kelly | Director | 4 Jul 2007 | 13 Oct 2008 | British | 85 years |
| John Davy | Director | 14 Dec 2009 | 20 Jan 2015 | British | 70 years |
| Jorn Vestergaard | Director | 1 Jun 2015 | 3 Oct 2016 | Danish | 58 years |
| Mary Josephine Erb | Secretary | 20 Oct 2008 | 27 Feb 2009 | British | - |
| Matthew Brabin | Secretary | 20 Jan 2015 | 13 Nov 2015 | - | - |
| Matthew Edward Stanley Brabin | Director | 20 Jan 2015 | 13 Nov 2015 | British | 61 years |
| Matthew Edward Stanley Brabin | Director | 1 Aug 2016 | 16 Jun 2020 | British | 61 years |
| Paul Andrew Cottam | Director | 4 Mar 2010 | 14 Mar 2011 | British | 60 years |
| Philip John Leigh | Director | 28 Feb 2019 | 28 Feb 2021 | British | 59 years |
| Philip Newton White | Director | 20 Feb 1991 | 19 Jan 1994 | British | 74 years |
| Philip Newton White | Secretary | 20 Feb 1991 | 19 Jan 1994 | British | - |
| Purvin Kumar Madhusudan Patel | Director | 16 Jun 2020 | 23 Dec 2020 | British | 53 years |
| Richard Anthony Roberts | Director | 19 Jul 2010 | 24 Nov 2010 | British | 61 years |
| Richard Ian Sykes | Director | 20 Jan 2015 | 1 Aug 2016 | British | 56 years |
| Robert Michael Gilbert | Director | 13 Jul 2004 | 31 Dec 2007 | British | 78 years |
| Robert Philip Painting | Director | 13 Jul 2004 | 10 Aug 2009 | British | 75 years |
| Ross Forman | Director | 14 Dec 2009 | 21 Jul 2011 | United States | 62 years |
| Ruth Scarr Hall | Director | 9 Dec 1996 | 14 Sept 2004 | British | 82 years |
| Ruth Scarr Hall | Secretary | 20 Feb 1994 | 14 Sept 2004 | British | - |
| Stephanie Louise Hamilton | Director | 22 Feb 2021 | 31 Jul 2021 | British | 55 years |
| Stuart William Graham | Director | 26 Oct 2007 | 27 Mar 2008 | British | 72 years |