Ultra-high vacuum spectroscopic techniques have proven to be valuable tools in elucidating the relationships between the structure and reactivity of surfaces. At least for catalytic systems, work in this area has been dominated by studies of the surface properties of metals. Over the last twenty years, however, surface science studies of catalytically active metal oxides have emerged and are now almost as prevalent as those of metals. In this talk I will give a historical perspective of surface science studies of metal oxides as well as describe the work of my own group in this area. Future challenges for studying the surface properties of oxides will also be presented.