The papers were previously in the ownership of Francis Edwards, Charles B. Lee and The Right Honourable the Earl of Gainsborough, and were purchased by the National Maritime Museum at auction between 1966 and 1979. They consist of Middleton's private correspondence and administrative papers. The latter cover the range of Admiralty and Navy Board subjects of business between 1778 and 1806. Originally Middleton arranged them all either by writer or alphabetically by subject; Sir John Knox Laughton may also have contributed to the arrangement. In so far as letters and administrative papers were largely separate, this arrangement has been retained, though extended and carried throughout the collection. Additional letters and papers, obviously added by John Deas Thompson, have been formed into a distinct section. A further group of papers was purchased from Lord Gainsborough via Christie's in 1994. Where possible these have been integrated into the existing catalogue sequence, from MID/1-MID/14. Further correspondence has been added in a new section, MID/15. Further information can be found in 'The Letters and Papers of Charles, Lord Barham...', edited by Professor Sir J.K. Laughton and published in three volumes by the Navy Records Society, 1907-1911.

Administrative / biographical background
Charles Middleton entered the navy as a captain's servant in 1741, was promoted a lieutenant in 1745 and post captain in 1758. In 1778 he became Comptroller of the Navy, a position he held until 1790. He was created a baronet in 1781 and, though holding a civil post, a rear-admiral in 1787, being made a vice-admiral in 1793 and admiral in 1795. In 1794-5 he was senior sea lord to Lord Spencer and in 1805-6, First Lord of the Admiralty. Between 1804 and 1807 he headed the Commission for revising and digesting the civil affairs of the navy, being made a peer in May 1805 on accepting the appointment as First Lord.