Established in 1887 to promote research that would benefit the British Empire. From 1893 it was housed in a building in Exhibition Road, designed by T. E. Collcutt. This was demolished in the 1950s/60s to make space for Imperial College. The Imperial Institute was renamed the Commonwealth Institute and moved into a building in Holland Park. The Library Time Machine has some marvellous pictures of the interior of both Institutes: the Imperial and the Commonwealth.
The 1959 film 'The Rough and the Smooth'/'Portrait of a Sinner' has a scene set at the entrance to this building, at about 52 mins. You see two of the lions and a highly ornate entrance area.