Founding date. (see next dossier). Chatham House — the building at 10 St James's Square, London — became the headquarters in 1923 and gave the Institute its familiar name.Council on Foreign Relations AGR Ch 1 citing Grose 1996; corroborated by Quigley AAE Ch 2). The British branch was incorporated 5 July 1920 as the British Institute of International Affairs; the "Royal" charter was granted in 1926; the American branch took shape separately as the Ben-Aharon Founded 30 May 1919 at the Hotel Majestic in Paris, in the joint proposal of the British and American Peace Conference delegations for "a permanent Anglo-American Institute of International Affairs, with one branch in London, the other in New York" (
Founding figures.; Lord Eustace Percy; the American side at the Hotel Majestic meeting included House, Shotwell, and the Inquiry circle. The Astor family (Waldorf and Nancy Astor) bought St James's Square and donated the building. Chatham House sat across the square from the Astors' London residence; Geoffrey Dawson edited Robert Cecil; principal British-side architect); Round Table Group Lionel Curtis (The Times; the Round Table-Chatham House-Times triangle is documented by Quigley AAE Ch 2 with exceptional precision: "The Council of the RIIA (which, by Curtis's energy came to be housed in Chatham House, across St. James's Square from the Astors, and was soon known by the name of this headquarters) and the board of the Council on Foreign Relations have carried ever since the marks of their origin."
Stated purpose vs structural role. Stated: a research institute for the study of international questions, with the "Chatham House Rule" (adopted 1927) providing the confidentiality that permits frank discussion among policy elites — the rule that participants may use information received but may not reveal speaker identity. Structural role: the operating headquarters of the Round Table Group's policy work in Britain from 1920 onward (Quigley AAE Ch 2); the British counterpart to the CFR with continuous personnel and policy-publication overlap; the publisher of the journal International Affairs from 1922 onward, which together with the Round Table Group's Round Table quarterly forms the principal British policy-publication network of the inter-war and postwar periods.
Cross-corpus triangulation. Documentary record. Quigley AAE Ch 2 is the foundational source: he documents the Round Table → RIIA continuity from inside the Group's records and identifies RIIA as Curtis's principal postwar institutional accomplishment. Tragedy and Hope extends the treatment with the parallel CFR story. Sutton ASE Ch 1 treats RIIA-CFR as a single trans-Atlantic formation. Osterrieder Welt im Umbruch II.2 documents the post-Versailles RIIA + CFR cofounding as the institutional completion of the 1917-18 Inquiry phase; "House was the principal American architect" of both. Boardman Mapping the Millennium "Heartland" theory (1904 Royal Geographical Society paper; 1919 Mackinder's foregrounds the RIIA's role in shaping British foreign-policy attitudes toward Russia across the inter-war and Cold War periods; Democratic Ideals and Reality 1997 Brzezinski) became the structural framework that RIIA carried forward, and that Grand Chessboard explicitly revived (BA-AGR-003). Ben-Aharon AGR Ch 1-3 carries this thread to the present. Supersensible register. RIIA does not appear by name in Steiner GA; the supersensible- tradition mapping operates at the level of the Round Table formation of which RIIA is the British institutional vehicle.
Load-bearing claims. WiU-22-010 (already in claims.jsonl;
referenced in manuscript) — RIIA / Chatham House founded 1919-20 in
direct continuity with the Round Table Group; institutional architecture
of Anglo-American foreign-policy elite from 1920 to the present
(confirmed_multi; Quigley AAE + Sutton ASE + Ben-Aharon AGR + standard
British-foreign-policy historiography). WiU-INST-010 — RIIA-CFR
institutional symmetry across the inter-war and postwar periods,
documented in Quigley AAE and corroborated by Grose's official CFR
history, establishes a coordinated Anglo-American policy-research network
that survived two world wars and the Cold War with continuous personnel
and publication output (confirmed_multi).
Evidentiary status. Existence, membership, Round Table continuity, and policy-publication output are uncontroversially documented; the mainstream British-foreign-policy literature treats RIIA as the central British think-tank of the twentieth century without contesting the Round Table genealogy. Disagreement concerns the weighting of RIIA influence on specific policy episodes (most contestedly: appeasement, the early Cold War, post-1989 Russia policy) rather than the institutional facts.
Minimum claim that survives skepticism. RIIA / Chatham House was founded in 1920 by the British wing of the 1919 Paris Peace Conference delegation, with the Round Table Group's Lionel Curtis as principal architect; it has continuously housed the principal British foreign- policy elite as a research and discussion forum from 1920 to the present, with Astor financial backing and Round Table operational continuity in its first half-century.
Cross-references. [→ dossier]. Events: 30 May 1919 Hotel Majestic meeting; 5 July 1920 BIIA incorporation; 1923 Chatham House occupancy; 1926 Royal charter; 1927 Chatham House Rule; 1922 Edward Grey (Philip Kerr) [→ dossier]; Geoffrey Dawson; Halford Halford Mackinder [→ mid-priority dossier]; Lord Lothian Persons: Lionel Curtis; Robert Cecil [→ dossier]; International Affairs founding.