From the mid-Eastern (Later) Han onward, the authority of the Three Excellencies gradually waned, while that of the Imperial Secretariats steadily increased. Since the Imperial Secretariats shifted from private attendants of the emperor to officials who managed the core affairs of government and participated in outside court politics, they were no longer involved in internal palace duties. To counterbalance this shift of power and to retain direct control over critical decisions, the emperor selected close palace attendants to review memorials submitted by the Imperial Secretariats and to assist in drafting and issuing responses, an arrangement that later evolved into the Chancellery Department. In some cases, separate confidential offices were also established to take over certain key duties from the Imperial Secretariats, laying the foundations for what would later be known as the Palace Secretariat Department.