Theta-pinch devices have produced fusion plasmas of high beta, temperature and density, with the first observation of thermonuclear neutrons recorded in 1958. Linear theta-pinch plasmas are neutrally stable and display good confinement properties before the onset of end effects. An end-shortening-induced instability, and axial particle and thermal losses dominate these plasmas. In Scylla IV-P, the plasma stability was enhanced and axial particle losses were eliminated by the use of material end plugs, but thermal losses remained unabated. Scyllac was a large-aspect-ratio, toroidal theta-pinch proposed to circumvent the end-loss problem. The high-beta-stellarator plasma produced in Scyllac was found to be unstable to a poloidal M 1 mode (sideways displacement). Experiments demonstrated feedback stabilization of the mode. Although experimental lifetimes were too short for transport issues to be addressed, Scyllac did demonstrate the existence of stabilized high-beta stellarator equilibria.