In 1783, John was appointed Vicar of Naseby, where he had already served as curate – a living he held for the rest of his life.
[6] In 1792, John Mastin published the first edition of The History and Antiquities of Naseby, in the County of Northampton by subscription.
Other material includes an account of agricultural practices, references to contemporary residents, and details of at least some of the memorials and tombstones then present in Naseby church and its churchyard.
The texts of both works are included with a learned introduction, annotations and several relevant appendices in a volume entitled A Georgian Country Parson: the Rev.
They are both commemorated on a slate plaque fixed to the west end of the inside south wall of Naseby Church.