Perovskite-type compounds can be both very simple and tremendously complex. Remarkably, even binary perovskite-type compounds may exhibit high level of complexity that leads to intriguing physical behavior. Recently, we discovered that Mn2O3 is non-perovskite at ambient pressure transforms into a perovskite-type structure around 20 GPa and 1200 K. This perovskite-type polymorph can be quenched to ambient conditions. It reveals several magnetic transitions and giant magnetically-driven ferroelectricity, with ferroelectric polarization ranging among the highest values observed in systems of this kind. We will use neutron diffraction on WISH to resolve magnetic structures as well as details of the crystal structure of perovskite-type Mn2O3. This experiment will help us to elucidate the origin of giant magnetically-driven ferroelectricity.