The foundation of cities and the articulation of urban networks are a persistent theme in the history of colonial Spanish America. As administrative-social service centers and as foci of trade and, sometimes, manufacturing, cities were the meeting ground of the policies of the metropolis and the concerns of its subjects, the local creoles, castas, and Indians. This mediating position has influenced the kinds of questions asked about cities by Latin American urban historians. Those who, with this author, believe that the city's administrative function was paramount, consider the following questions most useful in determining the role of urban centers within the Spanish empire: was city government merely the agent of the Crown, was it the spokesman of a local oligarchy, or did it permit some degree of popular participation? Was the operation of municipal government characterized by co-operation or by conflict? What was the relative importance of formal institutions created by the Crown, such as the cabildo and the real acuerdo, and informal institutions, such as the family and the client system, in the conduct of city business?