| Ailsa Elizabeth Tipping | Director | 12 Jun 2015 | 5 Apr 2016 | British | 61 years |
| Alexandra Clare Thomas Hathaway | Director | 10 Jan 2025 | 8 Sept 2025 | British | 52 years |
| Andrew Dancox | Director | 12 Jun 2015 | 13 Feb 2017 | British | 61 years |
| Christopher David Vaughan | Director | 13 Feb 2017 | 22 Jun 2023 | British | 62 years |
| Matthew Yates | Director | 28 Aug 2014 | 10 Jan 2025 | British | 49 years |
| Nicholas Theodore Cadbury | Director | 28 Aug 2014 | 12 Jun 2015 | British | 60 years |
| Nicholas Theodore Cadbury | Director | 13 Feb 2017 | 21 Mar 2022 | British | 60 years |
| Ratnesh Mohan Verma | Director | 12 Jun 2015 | 31 Jan 2019 | Indian | 57 years |
| Russell William Fairhurst | Director | 28 Aug 2014 | 12 Jun 2015 | British | 63 years |
| Stephane Laguette | Director | 12 Jun 2015 | 13 Sept 2015 | French | 63 years |