Short answers, pulled from the story.
The Royal United Services Institute was founded in 1831, making it the world's oldest defence and security think tank. The founding committee met on the 25th of June 1831, chaired by Major General Sir Howard Douglas.
The first Duke of Wellington founded RUSI, arguing in a letter to Colbourn's United Service Journal that a united service museum should be established for naval and military officers. Commander Henry Downes, Royal Navy, then assembled the founding committee.
RUSI is based in Whitehall, London. It has occupied its current purpose-built headquarters next door to the Banqueting House since 1895. In 2022, RUSI announced ten million pounds in funding for the redevelopment of that address.
RUSI is funded by individual and corporate members, publication revenues, and research contracts. Major contributors include the U.S. Department of State, the UK Foreign Commonwealth and Development Office, the European Commission, and BAE Systems.
Prospect magazine named RUSI Think Tank of the Year in 2008 and 2020, and Foreign Policy Think Tank of the Year in 2008 and 2011. In 2022 RUSI received the Foreign Affairs Award in Prospect's Think Tank Awards, and as of 2025 it ranks among the ten most cited think tanks in the world.
Rachel Ellehuus became director-general of RUSI in 2025, succeeding Karin von Hippel who served from 2015 to 2025. The institute is chaired by the ninth Duke of Wellington.