The Ulucami of Bursa was begun in 1396 during the reign of Bayazid I, and completed in 1399. It is a large rectangular building with the dimensions of 68 m. by 56 m. Twelve square piers divide the interior into twenty equal units, each of which is surmounted by a dome. The second dome from the main portal in the centml row is open on top. The unit below it has a pool in the centre. Its floor is finished with white marble slabs and is tower by two steps than the tloor of the prayer section. This part resembles an interior court. The domes of the Ulucami rest on pendentives and are enveloped on the exterior by octagonal drums. The centre row on the north-south axis has the highest domes; the hvo side rows diminish in height in two stages. The Ulucami of Bursa does not have a porch.