In 1870-72, John Marius Wilson's Imperial Gazetteer of England and Wales described Havengore like this:
HAVENGORE, an extra-parochial small island, in Rochford district, Essex; at the mouth of the Thames, nearly opposite the Nore light, 6 ½ miles E by S of Rochford. Acres, 810. Real property, £470. Pop., 25. House, 1. The property belongs to James Tabor, Esq.
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 Havengore has changed, please see our redistricted information for the modern district of Rochford. More detailed statistical data are available under Units and statistics, which includes both administrative units covering Havengore and units named after it.
GB Historical GIS / University of Portsmouth, History of Havengore, in Rochford and Essex | Map and description, A Vision of Britain through Time.
Date accessed: 30th May 2015
Click here for more detailed advice on finding places within A Vision of Britain through Time, and maybe some references to other places called "Havengore".