The Heywood Manuscript is a collection of handwritten copies of letters and poems of the Heywood family, and letters from their relatives and friends, which was completed in 1798, and to which some explanatory passages have been added. Most of the letters and poems are by Nessy and Peter Heywood, and the transcription and reproduction of their correspondence and poetry may have been instigated by Peter as a lasting monument to his sister Nessy, who had devoted herself to him and his release when he was imprisoned on "HMS Hector" awaiting his court-martial in connection with the Mutiny on the Bounty, and had died very young.