The National Archives (TNA) at Kew is the official archive and records publisher for the United Kingdom government, England, and Wales, established in 2003 through the merger of the Public Record Office and the Historical Manuscripts Commission. Holdings span the eleventh century to the present and include Crown, Treasury, military, judicial, and parliamentary records.
For Oak Island research, the archive is consulted primarily for British military records of the late-eighteenth century, Crown colonial-administration records bearing on Nova Scotia, and the Sir Henry Clinton papers. Rupert Furneaux's 1972 thesis that the Oak Island works were created by British military engineers under Sir Henry Clinton drew on TNA-held materials, and subsequent skeptical analyses have returned to the same source body.
Material is principally accessed in person at Kew. A growing portion of holdings is digitized and available through the TNA online catalogue and Discovery service. Some material remains under closure or restricted access pending review under public-records legislation.
What this source documents
British government and Crown records bearing on Oak Island context, including: Sir Henry Clinton papers and other late-eighteenth-century military records (drawn on by Rupert Furneaux's 1972 British-military thesis); Treasury and Audit records of the period; Crown colonial-administration records concerning Nova Scotia; British court and parliamentary records bearing on treasure-trove and Crown rights as exercised in the colonies.
Why it matters
For research questions involving British involvement in Oak Island theories, particularly the military-engineering hypothesis advanced by Furneaux and subsequent skeptical writers, The National Archives at Kew is the necessary archival reference. The archive does not validate or contradict any specific Oak Island theory; it preserves the British-side documentary record from which those theories draw.