The Imperial Diet was the assembly of the Holy Roman Empire from circa 1100 to 1806. After 1489 the Diet was divided into three chambers or colleges.
Seven Electors (lay and ecclesiastical princes) formed the electoral (first) college and were charged with electing a new emperor. The second college, also of princes, was composed of the other noble rulers, both lay and ecclesiastical. The third college represented delegates from the Imperial towns.
With the collapse of central authority during the Thirty Years' War, the Diet lost its legislative powers and became a largely ceremonial body.