What did Gregory VII issued and what he forbid of kings?

Pope Gregory VII issued the Dictatus Papae in 1075, which outlined the powers of the pope and asserted papal supremacy over secular rulers. He forbade kings from exercising authority over church appointments and insisted that only the pope had the power to appoint bishops and invest them with spiritual authority. This conflict with secular rulers, particularly with Emperor Henry IV, contributed to the Investiture Controversy, a significant power struggle between church and state during the Middle Ages.