It is well known that a metal‐bound hydroxido ligand is an efficient nucleophile around neutral pH. In a mechanistic sense, the presence and chemical reactivity of the coordinated hydroxido nucleophile are frequently invoked both in biomimetic chemistry and in numerous examples of hydrolytic metalloenzymes. In this review, we explore the background of this chemistry in order to attempt to trace the thinking which led to what is now a fully accepted mechanistic pathway.