The parish was the fundamental ecclesiastical institution brought by Spain to the New World, and perhaps even the principal instrument of empire. This pioneering study traces the origins and development of the parishes of a single Central American diocese from conquest to independence. Drawing widely on Guatemalan archive sources, it presents a detailed picture of the colonial church at parish level. During the eighteenth century almost all regular parishes were secularized. This brought to an end the ecclesiastical state within a state: a republic of priests and Indians. Although the Crown had decreed that the Christian faith had to be presented in its purest form, uncontaminated by worldly influences, a system of vested interests sprang up with the first conversions. Viewed in the most prosaic terms, her parochial incomes made the church the greatest business of the colonial period.