1831 - the Naval and Military Museum established by the Duke of Wellington. 1839 - renamed to the United Services Institution. 1860 - royal patronage was granted to the Institution. 1878 - gold medal prize introduced for essays submitted in alternate years on naval and military subjects. 1895 - moved to current premises on Whitehall. 1900 - gold medal introduced in 1878, superseded by the Chesney and Trench Gascoigne essay prizes. 2004 - name changed to Royal United Services Institute for Defence and Security Studies.

It promotes the study and discussion of developments in military doctrine, defence management and defence procurement. In recent years RUSI has broadened its remit to include all issues of defence and security, including terrorism and the ideologies which foster it and the challenges which we face from other man-made or man-assisted threats and from natural disasters.