The private secretary is the principal channel of communication between the monarch and the governments in most of the Commonwealth realms.

Constitutionally there was some opposition on the part of ministers to the creation of an office which might grow to have considerable influence upon the sovereign.

Until 1965, peerages granted to Private Secretaries were hereditary baronies, with the exception of Lord Knollys, who was created a viscount in 1911.

The same is true for Principal Private Secretaries to other members of the Royal Household, such as William, Prince of Wales.

The private secretary has general oversight of security policy, though the master of the household is also involved, and the keeper of the Privy Purse has responsibility for the ceremonial bodyguards, such as the gentlemen at arms and the yeomen of the Guard.