In 1870-72, John Marius Wilson's Imperial Gazetteer of England and Wales described Tarrant Keynston like this:
TARRANT-KEYNSTON, a parish in Blandford district, Dorset; 2 miles NE of Spetisbury r. station, and 3 ESE of Blandford. Post town, Blandford. Acres, 1,962. Real property, £2,190. Pop., 309. Houses, 73. Most of the property is in one estate. The living is a rectory in the diocese of Salisbury. Value, £394.* Patron, the Rev. J. Ansten. The church is good.
Tarrant Keynston is now part of North Dorset district. Click here for graphs and data of how North Dorset has changed over two centuries. For statistics about Tarrant Keynston itself, go to Units and Statistics.
GB Historical GIS / University of Portsmouth, History of Tarrant Keynston in North Dorset | Map and description, A Vision of Britain through Time.
Date accessed: 30th March 2017
Click here for more detailed advice on finding places within A Vision of Britain through Time , and maybe some references to other places called " Tarrant Keynston ".