Model complexes of the natural photosynthetic Water Oxidation Complex (WOC) of Photosystem II (PSII) have been prepared. These compounds contain [Mn₄O₄]⁷⁺ cubic cores, and are seen to exhibit photoinduced water splitting. Indeed, conditions have been discovered that enable these manganese-oxo cubanes to catalyze the sustained photo-assisted oxidation of water, for several thousand turnovers. The capture of light energy to drive this oxygen-evolving half reaction is considered key to future renewable energy production. The properties of these compounds are being vigorously explored to allow for integration into a photoanode, as a component of a photoelectrochemical cell (PEC).