 While Arlesheim was probably under the influence of Basel through the counts of Birseck, it never entered into a Burgrecht treaty with the city.Despite Arlesheim's loose connection with Basel, it converted to the new Protestant faith in 1528 when Basel converted.About half a century later, in 1582, the Bishop of Basel, Jakob Christoph Blarer von Wartensee, succeeded in spreading the Counter-Reformation in Arlesheim.