Ambrogio Lorenzetti
Effects of Good Government on the City
Fresco in the Palazzo Publico (Siena, 1338-1340)

For details of the fresco, click on the following links:

Dancing
Dancing (larger)
Justice
Men
Sovereign and Subjects

For a masterful analysis of the political philosophy embedded in this fresco, see Quentin Skinner, "Ambrogio Lorenzetti and the Portrayal of Virtuous Government" and "Ambrogio Lorenzetti on the Power and Glory of Republics," in Skinner, Visions of Politics, Vol. 2 (Cambridge: Cambridge University Press, 2002), pp. 39-117.