During the reign of Bayezid the Lightning, a large construction was carried out in Bursa. It was then that the Great Mosque (1396-1400) was built by order of the Sultan. It was the first multi-domed structure of its kind in the Ottoman Empire. Until now, the Ulu Cami (Great Mosque) remains the most monumental building in Bursa. Its twenty domes are supported by twelve square pillars. Directly under the central dome there is an unusually shaped ablution fountain, which is a pool-fountain with three bowls inside.
For the first time, Ulu Jami suffered during the invasion of Timur. The second serious damage was caused by an earthquake in 1855. After it, the mosque underwent extensive restoration work. Due to its architectural merits, as well as the examples of art of calligraphers and wood carvers decorating the interior, Ulu Cami is one of the most interesting historical monuments of Bursa.