| Alison Ann Hargreaves | Secretary | 9 Aug 1993 | 13 Aug 1999 | British | - |
| Anthony Blake Wyand | Director | 1 Jan 1999 | 11 Oct 2002 | British | 83 years |
| Anthony William Searson James | Director | 18 Mar 2011 | 12 Sept 2013 | British | 58 years |
| Christopher James Jukes | Director | 1 Apr 2014 | 27 Sept 2019 | British | 48 years |
| David Alexander Cospatrick Home | Director | 13 Oct 1993 | 14 Dec 2000 | British | 83 years |
| Deborah Clare Lee | Director | 27 Sept 2019 | 28 Mar 2022 | British | 50 years |
| Douglas Robert Jan De Broekert | Director | 27 Sept 1991 | 31 Dec 1998 | British | 87 years |
| Geoffrey Harold Benjamin Carter | Director | 27 Sept 1991 | 31 Dec 1994 | British | 97 years |
| George Ian Macloy Cockburn | Director | 1 Apr 1993 | 31 Dec 1997 | British | 81 years |
| Gerald Cavendish | Director | 27 Sept 1991 | 11 Oct 2002 | British | 75 years |
| Hugh Alexander Cromar Edwards | Director | 27 Sept 1991 | 1 Jul 1998 | British | 90 years |
| Ian Douglas Mair | Director | 28 Mar 2022 | 27 Jun 2024 | British | 53 years |
| Ian Duncan Chisholm | Director | 31 Dec 2021 | 31 Dec 2023 | British | 59 years |
| Ian Michael Philip Staines | Director | 27 Sept 1991 | 31 Dec 1991 | British | 95 years |
| James Creyke Hulton Whitty-lewis | Director | 28 Mar 2022 | 31 Mar 2025 | British | 45 years |
| Jeremy Henry Moore Newsum | Director | 27 Sept 1991 | 10 May 2005 | British | 71 years |
| John Nigel Courtenay James | Director | 27 Sept 1991 | 31 Dec 2000 | British | 91 years |
| John Richard Sclater | Director | 27 Sept 1991 | 11 Oct 2002 | British | 86 years |
| Jonathan Osborne Hagger | Director | 27 Sept 1991 | 10 May 2005 | British | 77 years |
| Jonathan Osborne Hagger | Secretary | 13 Aug 1999 | 10 May 2005 | British | - |
| Judith Patricia Ball | Secretary | 10 May 2005 | 9 May 2019 | British | - |
| Kurt Fridolin Viermetz | Director | 1 Jul 1998 | 11 Oct 2002 | German | 87 years |
| Mark Antony Loveday | Director | 1 May 1999 | 14 Dec 2000 | British | 83 years |
| Mark Robin Preston | Director | 30 Jun 2006 | 28 Mar 2022 | British | 58 years |
| Michael Douglas Trollope Loup | Director | 27 Sept 1991 | 1 May 1994 | British | 97 years |
| Nicholas Richard Scarles | Director | 5 May 2006 | 31 May 2019 | British, | 64 years |
| Peter Sean Vernon | Director | 28 Mar 2017 | 30 Sept 2021 | British | 67 years |
| Ralph William Hayward | Director | 1 Jul 1998 | 11 Oct 2002 | British | 83 years |
| Richard Allan Jeffrey Marshall | Director | 12 Jun 2015 | 31 Dec 2021 | British | 62 years |
| Richard Baker Wilbraham | Director | 27 Sept 1991 | 30 Apr 1999 | British | 92 years |
| Robin Shedden Broadhurst | Director | 1 Jan 2001 | 11 Oct 2002 | British | 80 years |
| Sally Margaret Doyle Linden | Director | 5 May 2006 | 1 Oct 2007 | British | 67 years |
| Stephen Howard Rhodes Musgrave | Director | 1 Jan 1999 | 30 Jun 2006 | British | 73 years |
| Stephen Jeremy Moore | Director | 10 May 2005 | 30 Jun 2023 | British | 66 years |
| Stuart Robert Hartley Beevor | Director | 11 Oct 2002 | 17 Mar 2011 | British | 69 years |
| William Robert Holland | Secretary | 27 Sept 1991 | 9 Aug 1993 | British | - |