Earlier, non-moving, forerunners were the panoramas and the peepshows of the streets and fairgrounds as depicted by William Hogarth in his engraving of Southwark Fair.

[1] It featured fourteen peepholes onto perspective scenes using large convex lenses, mirrors and special lighting to create scenic effects.

[1] In the 1820s London was experiencing a building boom and John Nash's grand plan for Regent's Park and its fashionable terraces was well underway.

James Arrowsmith, brother-in-law of Louis Daguerre, commissioned the architect Augustus Charles Pugin, who was working for Nash at the time, and the builder Jacob Smith to design and build a Diorama during the summer of 1823.

[2] The audience of up to 200 sat thirty to forty feet from the canvases in a dark circular "saloon" at the centre of the building which was "tastefully decorated, and fitted up with boxes and a pit".

[3] The saloon was rotated through 73 degrees by an arrangement of wheels beneath its timber frame so that the two huge painted scenes could be displayed alternately in the two "picture rooms".

The machinery, designed by James Morgan and built by an engineer called Topham, was so well poised that the whole auditorium could be turned by a single man.

[4] The artist John Constable went to the opening and wrote to his friend, Archdeacon Fisher: "It is in part a transparency, the spectator is in a dark chamber, and it is very pleasing and has great illusion.

At the back of the choir the church is illuminated, and the congregation arriving take their places in front of the chairs, not suddenly, as if the scenes were shifted, but gradually.

The twenty years after the College vacated in 1973 saw a series of planning applications in an attempt to find a long-term use for the Diorama, during which time it was used as an artists' and actors' co-operative.

Planning consent was finally granted in 2020 to return the two flanking town houses, 17 & 19 Park Square East, to separate residential use, and retain the Diorama as offices.