The role of the private secretary to a Secretary of State originated in the 18th century. Today, a junior minister may have a three-person private office consisting of a Private Secretary and two Assistant Private Secretaries; whereas a more senior minister may have a five-person private office consisting of a Senior Private Secretary, Private Secretary and three Assistant Private Secretaries. The same applies to a Cabinet-level minister's private office but on a larger scale, due to a cabinet minister usually being responsible for entire, government departments and agencies.