The papers consist of twenty-seven volumes, partly of Dartmouth's own papers and partly of journals by his contemporaries. In the first category is the log of the ROYAL KATHERINE, 1673; the letter and order book of the Sub-Commissioners of Prizes at Portsmouth, 1672 to 1674; papers relating to Tangier, which include three letterbooks, two order books and a journal of the proceedings of Samuel Pepys and others, enquiring into the properties of the papers not directly relating to Dartmouth include a commonplace book, 1666; two logs, 1671 to 1672, 1672 to 1673, of Sir Edward Spragge; a log of the RESOLUTION, Captain Sir Thomas Allin (1612-1685), 1669 to 1670, Mediterranean; the log of the Assistance, Captain Sir Richard Munden (1640-1680), during the expedition to St Helena in 1673; a log of the SAUDADOES, Captain James Jenefer, 1672 to 1673, on a voyage to Lisbon; a log of the CENTURION, Captain Charles Wyld on a voyage conveying Sir John Finch (1626-1682), as ambassador to Constantinople, 1673 to 1674, and a log of Captain Grenvile Collins (fl.1679-1693), surveying in home waters, 1688 to 1689. There is a letterbook, 1666, of Prince Rupert and George Monck, Duke of Albemarle (1608-1670), joint Commanders-in-Chief. This was published as 'The Rupert and Monck Letterbook, 1666', ed. J.R. Powell and E.K. Timings (Navy Records Society, 1969). There are copies of the Duke of York's Sailing and Fighting Instructions, 1672 and 1673, accounts of the battle of Solebay, an account of the battle of Texel by Sir John Narbrough (1640-1688) and notes on seventeenth century naval affairs. The papers are described in the Historical manuscripts Commission's Eleventh Report (appendix, part v, 1887) and Fifteenth Report (appendix, part i, 1896). A further volume, a 'Discourse on the state of the Navy', 1660 to 1661, by Sir Robert Slingsby (1611-1661), was acquired in 1951.

Administrative / biographical background
Legge served with his cousin, Sir Edward Spragge (d. 1673), in the Second Dutch War, 1665 to 1667. During the Third Dutch War, 1672 to 1674, he was Captain of the Fairfax, under Sir Robert Holmes (1622-1692) and took part in the battle of Solebay, 1672. In 1673, he commanded the Royal Katherine, under Prince Rupert (1619-1682). He held various posts in the household of the Duke of York and was Lieutenant-Governor, then Governor, of Portsmouth from 1670 to 1682, when he was appointed Master-General of the Ordnance; he was created Baron Dartmouth in the same year. In 1683 he was sent to Tangier to supervise the evacuation. After the accession of James II in 1685, he was appointed Admiral of the Fleet in 1688, in the hope that he would be able to use the fleet to prevent the invasion of the Prince of Orange. This he was unable to do and he took the oath of allegiance to William and Mary in 1689. In 1691 he was accused of plotting on behalf of the exiled James and died while imprisoned in the Tower of London.