After the Types I and II of the Royal Württemberg State Railways had been manufactured in the USA, the Type III was the first locomotive to be built in Württemberg. However, some of the locomotives also came from Bavaria. In the years between 1846 and 1854, the Kessler company, its successor Maschinenfabrik Esslingen and the Munich Maffei built a total of 46 of these locomotives. They had an external frame and cylinders mounted horizontally on it with Stephenson valve gear. A four-sided firebox and an oval boiler barrel were each clad in wood. Since the 1960s they have been converted to more modern types, with the last examples being in service until 1913.