In 1861 Thorne was separated from Clarendon and joined with Leslie to form a new municipality, with James Martin as its first mayor. At that time its population of 465 was made up of people of mixed national origin.
Ten years later, when the municipality was separated from Leslie under the mayoralty of John Rennix, it had seen and influx of German settlers.
Thorne's main village, Ladysmith, was first called Upper Thorne Centre. Later, the name Danzig was proposed, but in 1902, at the end of the Boer War, the name Ladysmith was chosen to honor a village in South Africa.