Historical Perspective -- Bond Valence Theory -- Bond valence parameters and atom sizes -- Practical considerations in determining bond valence parameters -- The equal valence rule and crystal chemistry -- Using bond valences to model the structures of ternary and quaternary oxides -- Energy storage and ionic conduction -- Polymerization, Crystallization and Dissolution in Aqueous Solution: A Bond-valence Approach -- Structure and Reactivity in Aqueous Solutions and Oxide-Water Interfaces -- Analysis of solid surfaces -- Bond Valences in Education.