In 1870-72, John Marius Wilson's Imperial Gazetteer of England and Wales described Ilmer like this:
ILLMIRE, or ILMER, a parish in Wycombe district, Bucks; near Icknield street and the boundary with Oxford, 2½ miles NW of Princes-Risborough r. station. Post town, Princes-Risborough, under Tring. Acres, 674. Real property, £1, 230. Pop., 79. Houses, 16. The property is divided among a few. The manor belongs to the Earl of Chesterfield. Illmire House is a chief residence. The living is a vicarage, united with the rectory of Horsendon, in the diocese of Oxford. The church is early perpendicular, and was recently restored.
A Vision of Britain through Time includes a large library of local statistics for administrative units. For the best overall sense of how the area containing Ilmer has changed, please see our redistricted information for the modern district of Wycombe. More detailed statistical data are available under Units and statistics, which includes both administrative units covering Ilmer and units named after it.
GB Historical GIS / University of Portsmouth, History of Ilmer, in Wycombe and Buckinghamshire | Map and description, A Vision of Britain through Time.
Date accessed: 26th June 2016
Click here for more detailed advice on finding places within A Vision of Britain through Time, and maybe some references to other places called "Ilmer".