The Great Model was the cathedral design proposal designed by Sir Christopher Wren and made by William Cleere. The proposal put forth was denied, and Wren soon produced another revised design. However, many claim St Paul's Cathedral nonetheless bares an unmistakable resemblance to the Great Model and Wren's original intentions.
Made to scale of 1:25, the model was intended to be a permanent record in case of accident to the architect and to show, better than only drawings could, how everything fitted together.
The model was completed by August 1647 at a cost of about £600, the cost of a good London house. Originally it was painted "stone colours" inside and out, with grey for the lead of the domes, gilded details and fictive relief.
It was designed to be walked through at eye-level to suggest the experience of the real interior. The model was made from full-size drawings scaled up by Wren and his assistant Edward Woodroffe, working at a large table in the convocation house. For most of its life it has been kept in the cathedral. Although it shares broadly the same appearance as the finished building, there are significant differences between this presentation model and the cathedral as built. Some of the most notable changes were: the extension of the quire, changes to the West front and the introduction of the bell towers in place of a bell cupola half way down the nave.