| title | ISBN-13 | year of publication |
|---|---|---|
| The Emperor and the Army in the Later Roman Empire, AD 235-395 | 978-0-367-88068-2 | 2019 |
| The Emperor and the Army in the Later Roman Empire, AD 235 - 395 | 978-1-4724-5759-2 | 2017 |
| Theodosius and the Limits of Empire | 978-1-138-10298-9 | 2020 |
| The Wind-up Letters: From a Man With Too Much Time on His Hands | 978-1-84024-534-9 | 2006 |