Prousa (modern Bursa) was a city of Bithynia. Rarely mentioned before the 12th century, Prousa appears as a military base in the time of Justinian I, and as the site of a renowned hot spring frequently visited by Byzantine emperors. During the Iconoclastic period, Prousa was the regional center for the monks of the neighboring Mt. Olympos. The city gained in importance under the Komnenoi, when it was exposed to Turkish attack. In 1184 it revolted against Andronikos I, who took it in spite of its powerful fortifications. The city, described as built on a hill and surrounded by strong walls, was besieged in vain by the Latins in 1204-5. Prousa was threatened by Osman in 1302 and bought peace after a siege in 1304. According to Turkish sources Osman surrounded it with blockading fortresses in 1315; it was finally forced to surrender in 1326 and to pay a tribute of 30,000 gold pieces. Prousa was a suffragan bishopric of Nikomedia; it briefly assumed the name Theopolis in the 7th century and was made a metropolis by Isaac II Komnenos.