The vakfiyye from circa 1400 lists a mosque, a dervish lodge (zaviye), two madrasas (medrese), a hospital (darüssifa), a hamam, an imaret, a han, an imperial palace, kitchens, servants' quarters and a depot in the imperial complex of Bayezid I, completed in 1395. A mausoleum (türbe) for the sultan was commissioned and built in 1406 by his son Süleyman Çelebi. Based on the evidence of some remains, Gabriel hypothesized the presence of an enceinte built for the protection of the complex given its location away from the city. Of the many buildings, the mosque, the mausoleum, a madrasa, the hamam and hospital are remaining.
The mosque went through successive renovations in 1634, 1848, 1855-1874 (following the Bursa earthquake) and more recently in 1948, carried out without altering the original form. It is based on a reverse T-plan with a five-bay portico leading through a vestibule to a central hall flanked with eyvans on the east and west and a larger eyvan with the mihrab niche to the south. Four additional rooms located to the north and south of the side eyvans are accessed from the central hall. The southern wall of the northern rooms has been fitted with ornate plaster shelving with fireplaces (ocak) at the center. Stairs lead to the upper floor from the vestibule at the entrance where a corridor along the front façade meets the minaret steps. On the interior, the central hall and the prayer hall are crowned with domes; the lower dome of the prayer hall is supported on a chevron band. Beneath, the heavy hipped arch of the prayer hall meets the ground with muqarnas niches at each end, the feature known as "the Bursa arch."
On the northern façade, the marble portico with its inner and outer arches, muqarnas mihrab niches and balconies create a dynamic composition. The balconies serve as a landing for the stairs behind the façade. The casement windows on all façades are bordered with marble toothing, molding and inscriptions in relief and crowned with ogee tympana. The two minarets, which were rebuilt following the earthquake of 1855 have since collapsed, the single minaret on the western side of porch dates from 1972.
The mausoleum was built lower on the hill to the north of the mosque by architect Ali bin Hüseyn and is composed of a single domed room with a three-bay domed portico. The entry arch of the portico falls on two slender Byzantine columns of red marble. Restored following the Karamanoglu attack in 1414, the mausoleum was completely rebuilt after the earthquake.
The remaining of the two madrasas is sited next to the mausoleum, to the northwest of the mosque. It is composed of twenty cells around a long courtyard with now glazed gallery and basin at the center. The entrance is at the northwest and a large classroom (dersane) occupies the opposite end. The individual rooms were covered with cradle vaults and equipped with ocaks; the building has been greatly altered for its current use as the tuberculosis institute. It is made of two courses of brick to one course of stone.
The baths (hamam) on Yildirim Street to the southwest of the mosque is still in use but has lost its original character. The hospital, a building similar in plan to the medrese located on the east, is now in ruins; it used to have fourteen rooms with individual access to a circulating sewerage drain.
Baykal, Kâzim. Bursa ve anitlari. Turkey: Türkiye Anit-Çevre Turizm Degerlerini Koruma Vakfi, 1982.
Gabriel, Albert. Une capitale turque, Brousse-Bursa. Paris: E. de Boccard, 1958.
Goodwin, Godfrey. A history of Ottoman architecture. 1971. Reprint, Baltimore: Johns Hopkins Press, 1997.