The collection consists of 40 boxes of material. The bulk of the collection relates to the period following Lewin's retirement from the Navy. There are substantial amounts of lecture notes, together with correspondence concerning political matters such as Defence policy and organisation, and the Falklands conflict. Also prevalent is a large amount of correspondence with various maritime societies such as the George Cross Island Association, the Siege of Malta anniversary committee. There is a small amount of naval documents, including midshipman's journals from HMS VALIANT, Order books for HMS CORUNNA, URCHIN and HERMES, Lewin's pay book from 1949 and his 'mentioned in dispatches' certificates ('flimsies'). Also included is a folder concerning the loss of HMS SOMALI, (a destroyer that was torpedoed and then broke in two while being towed by HMS ASHANTI), photograph albums of the aircraft carrier, HMS HERMES, and a notebook kept by Lewin as Chief of Defence Staff during the Falklands campaign. The 'Personal Papers' section includes school reports and certificates, together with honours such as his Barony, Grant of Arms and Warrant of Appointment. The collection is also well served with photographs of Lewin at varying stages of his career. The collection is arranged into six sections or series:

LWN/1: Official records of Lewin's naval career.
LWN/2: Naval career- unofficial material: Folders of background material collected by Lewin, often including official government reports and papers.
LWN/3: Post naval career: public projects as Admiral (retired): Correspondence, lecture material and public projects Lewin became involved with after retiring from the Royal Navy.
LWN/4: Post naval career: personal correspondence: Personal correspondence relating to various projects in which Lewin became involved after retirement from the Royal Navy.
LWN/5: Personal papers: school reports, honours and photographs.
LWN/6 Personal papers: biographical material.

Administrative / biographical background
Terence Lewin was born in Dover in 1920. Educated at the Judd School in Tonbridge, he joined HMS BELFAST as a naval cadet shortly before the outbreak of war in 1939. After serving aboard the battleship HMS VALIANT, Lewin joined the destroyer HMS ASHANTI. In ASHANTI, he took part in convoys to Murmansk and later to the Mediterranean as part of Operation Pedestal, the vital convoys keeping Malta supplied. Lewin distinguished himself in action, being mentioned in dispatches 3 times and was awarded the DSC. After the war he rose to post rank and commanded the destroyer CORUNNA, before the Dartmouth Training Sqaudron, and then in the Indian Ocean in 1967, the aircraft carrier HMS HERMES in the lead up to the Arab-Israeli war. Lewin was made Rear Admiral in 1968 and by 1977 had become First Sea Lord. As Chief of Defence Staff, he played a prominent role in the decision to replace the Polaris missile system with the Trident system. Also as Chief of Defence Staff, he was Mrs Thatcher's main military adviser during the Falklands conflict (1982), for which, on his retirement, he was made a life peer (1982) and KG in 1983. In retirement he was as active as ever, patron of many societies and much in demand as a public speaker on naval and maritime subjects. He was Chairman of the National Maritime Museum between 1983 &1995. He was also President of the George Cross Island Association and played a leading role in planning the 50th Anniversary of the siege of Malta and the giant memorial bell erected in its memory. He also became very interested in the explorations of Captain Cook and contributed to the foundation of a Cook museum in Middlesbrough. Lewin died in 1999, aged 78. See also Richard Hill's biography of the Admiral, 'Lewin of Greenwich' (2000).