The Holy Roman Empire had the Imperial Diet ("Reichstag"). The clergy was represented by the independent prince-bishops, prince-archbishops and prince-abbots of the many monasteries. The nobility consisted of independent aristocratic rulers: secular prince-electors, kings, dukes, margraves, counts and others. Burghers consisted of representatives of the independent imperial cities. Many peoples whose territories within the Holy Roman Empire had been independent for centuries had no representatives in the Imperial Diet, and this included the Imperial Knights and independent villages. The power of the Imperial Diet was limited, despite efforts of centralization.