Permanent Under-Secretary of State for Defence

The permanent under-secretary of state for defence, also called the permanent secretary to the Ministry of Defence, is the permanent secretary at the Ministry of Defence. The office holder is the government's principal civilian adviser on Defence matters. The office holder is a member of the Defence Council and the Defence Board. They are the MOD principal accounting officer, and are called to give evidence to the Defence Select Committee.
The position has existed in its current format since the formation of the modern Ministry of Defence in 1964. It was preceded by the permanent secretary at the earlier Ministry of Defence (1947–1964), and by the permanent secretaries at the government departments that were absorbed into the Ministry of Defence in 1964: the permanent secretary to the Admiralty, the permanent under-secretary of state for war, and the permanent secretary to the Air Ministry.
The current permanent secretary to the MOD is David Williams.

Responsibilities

Leading defence ;
Setting strategy for defence, including corporate strategy ;
Heading the Department of State and the MOD Civil Service;
Providing policy advice to ministers and leading the relationship with other government departments;
The overall organisation, management and staffing of defence;
Performing the full range of Accounting Officer responsibilities, including the delegation of financial and other authority and accountability to senior colleagues, with personal accountability to Parliament for the economic, efficient and effective use of defence resources.

The permanent secretaries at the earlier Ministry of Defence (1947–1964):