I thought I would post links to data from a big project we funded some time back to capture English historical place-names. The data drives the Historical Gazetteer off England’s Place-names where you can search for individual modern forms to find the historical name.
We had previously provided an automated system for using the data in place-name research via our Unlock service. As that service has been discontinued, I am providing links to the raw MADS (Metadata Authority Description Schema) files, which you can download and use if you are want to develop your own system.
The Digitisation of English Place-names MADS data is licensed to Jisc by the English Place Names Society and released under a Creative Commons Attribution-NonCommercial 4.0 International License. You can also find a simple list of all the links to the files here (note that the list on that page does not display the county names).
Links to the counties