In an embodiment, a switching circuit is provided that includes a Group III nitride-based semiconductor body including a first monolithically integrated Group III nitride-based transistor device and a second monolithically integrated Group III nitride based transistor device that are coupled to form a half-bridge circuit and are arranged on a common foreign substrate having a common doping level. The switching circuit is configured to operate the half-bridge circuit at a voltage of at least 300 V.