Jane Austen's only complete surviving manuscript is going on show in her home village of Chawton, Hampshire.
Austen probably wrote the play to be performed by her family
The 52 handwritten pages of Sir Charles Grandison reveal the author's only surviving play of any length.
It is a light-hearted dramatisation of scenes from The History of Sir Charles Grandison by Samuel Richardson, one of Austen's favourite novelists.
The play is unveiled on Thursday at Chawton House Library, a manor house once owned by Austen's brother.
Experts believe Austen wrote the play to be performed by her family at their former home in Steventon, near Basingstoke - beginning it about 1791-2 and adding more in 1800.
The pages, which had been carefully preserved by the Austen family, were discovered in 1977 and not published until 1980.
Brian Southam, chairman of the Jane Austen Society, is giving a talk at 1830 GMT to accompany the display.
Dr Jennie Batchelor of the University of Southampton said: "Chawton House Library is very fortunate to have this rare 52-page manuscript by Jane Austen, the only complete manuscript to have survived from her adult writing career."
Chawton House, a Grade ll listed Elizabethan manor house, is now a library and study centre for pre-1830 women's writing.