By 1272 the prince-bishops of Speyer had won half of Dielheim. Prince-bishop Adolf, who was in desperate need of money, pawned his half of Dielheim to Conz Mönch of Rosenberg in 1380. Conz Mönch took the other half of the village in the following years, thereby putting Dielheim in the possession of a noble for the first time. Conz Mönch, to ensure his control of the area, had a simple castle built on the Teufelskopf. This castle was probably more like a fortified farm than a proper castle. The isolated fortification could not be maintained for long and was quickly described as abandoned. Less than 200 years later, the castle appears as a place name. After multiple changes in ownership and having been pawned many times (noble families documented in this period include von Sickingen, von Rosenberg, von Menzingen, von Neipberg, von Gemmingen as well as the prince-bishops of Speyer), Dielheim finally came as a whole into the ownership of the prince-bishops of Speyer in 1512. The administrative seat of Dielheim for the prince-bishop was in Rotenberg. In the German Peasants' War in 1525, many farmers from Dielheim fought on the side of the so-called Mob of Malsch ("Malscher Haufens") against the oppression of the rule of the prince-bishops. After the defeat of the revolt, the village had to suffer harsh penalties. In the Thirty Years' War, Dielheim was almost completely destroyed by the troops of the Electorate of the Palatinate of the Rhine, the Holy Roman Empire, and Sweden. The region recovered only slowly from the loss of people and buildings.