Before the adoption of the portfolio system in the Government of India, all Governmental business was disposed of by the Governor-General in Council, the Council functioning as a Joint Consultative Board. As the amount and complexity of business of the Government increased, the work of the various Departments was distributed amongst the members of the Council, only the more important cases being dealt with by the Governor-General or the Council collectively.
This procedure was legalized by the Indian Councils Act, 1861 during the time of Lord Canning, leading to the introduction of the portfolio system and the inception of the Executive Council of the Governor-General. The Secretariat of the Executive Council was headed by the Private Secretary to the Viceroy, but he did not attend the Council meetings. Lord Willingdon first started the practice of having his Private Secretary by his side at these meetings. Later, this practice continued and in November, 1935, the Viceroy's Private Secretary was given the additional designation of Secretary to the Executive Council. But these posts were separated subsequently, and a separate Secretary was appointed to the Executive Council as distinct from the Private Secretary to the Viceroy and Governor General.
Constitution of the Interim Government in September 1946 brought a change in the name of this Office. On 5th September, 1946, the Secretariat of the Executive Council was designated as Cabinet Secretariat, and the Secretary to the Executive Council as Cabinet Secretary. It seems, however, at least in retrospect, that Independence brought a sort of change in the functions of the Cabinet Secretariat. It no longer remained concerned with only the work of circulating papers to Ministers and Ministries, but developed into an organisation for effecting coordination between the Ministries.