Note: starting from this edition, the coordinate transformation has been modified to use the official OS transform (slower but more accurate) from their national coordinate system (OSGB36) to the WGS84 coordinate system used by many, including OSM. This results in the data not aligning precisely to previous conversions; the misalignment can vary between 0 and around 5m, depending on the location. This is enough to be noticeable when zoomed in, but insufficient to render the existing OSM admin boundaries unusable. You are encouraged to realign to the new baseline for future work.
Historic Counties of England, Scotland and Wales