The feasibility of a 1.2kV GaN switch based on two series-connected 650V GaN transistors is demonstrated in this paper. Aside to achieve ultra-fast transitions and reduced switching energy loss, stacking GaN transistors enables compatibility with high-voltage GaN-on-Silicon technologies. A proof-of-concept is provided by electrical characterization and hard-switching operation of a GaN Super-Cascode built with discrete components. Further investigations to enhance stability with auxiliary components are carried out by simulations and co-integrated prototypes are proven at wafer level.