Complex sentence: The lathe was the most westerly of the lathes into which Kent was divided and the boundary of the Lathe with the rest of Kent is still in existence, with minor deviations, as the boundaries of Dartford and Sevenoaks with the rest of Kent.
Split into simpler sentences: The lathe was the most westerly of the lathes into which Kent was divided. The former boundary of the Lathe with the rest of Kent is now, with minor deviations, the boundaries of Dartford and Sevenoaks with the rest of Kent.