For an understanding of why an art movement becomes dominant in any period it is necessary to look at some of the ideological and political views and social needs of its practitioners, its patrons, and even its critics. In many eras—say the medieval age or the Renaissance—artists and their patrons, power and ideology, were at one with each other. The artist was integrated with the established process of thought and government; the ideas of the artist and the needs of the patron were agreed upon by both. Personal caveats, when they existed, were rarely deliberately reflected in commissioned visual art—and scarcely any sculpture and painting came into being outside of direct commission. Art was made to order, as today's public buildings are still custom built for a specific purpose and to a prescribed plan. The goal to be achieved in a particular image destined for a known location—a fresco on the wall of a church, a portrait of a pope or potentate—was clearly defined, as was the technique, often by contract. Both the artist and the patron knew exactly the audience toward which the work of art was directed.