The mosque for the Complex of Mehmet I, known as Yesil (Green) Mosque, was built between 1419-1421 by architect Haci Ivaz Pasa. The building went under extensive renovation following the earthquake in 1855, led by architect Parveillée.
The mosque is based on a reverse T-plan with a vestibule at entrance leading to a central hall flanked by eyvans on the east and west and a larger eyvan with mihrab niche on the south. Two small eyvans flank the entryway above which the royal box (hünkar mahfili) is located. There are four rooms with fireplaces (ocak) to the north and south of side eyvans accessed through the vestibule and the central hall respectively. Stairs on both sides of the vestibule lead to the upper floor where the royal lodge and two adjacent rooms for the royal women are located. Here, a passage opens to the balconies on the northern façade where the minaret steps begin. A portico was designed but never built.
The interior of the mosque is decorated with a mosaic of blue green tiles on walls and ceiling of eyvans from which it gets its name. (The exteriors of domes, now clad with lead, were once also adorned with blue green tiles.) The northern eyvans, the royal lodge and the mihrab are embellished with tiles bearing polychromic flower motifs and scriptures in relief. There are many 19th century replacements among the tiles. There is also little left of the polychromic paintwork that used to embellish the rooms. The doors and window shutters are adorned with interlaced motifs carved on wood. Light reaches the dim interior through windows pierced into the drums of domes as well as through windows on exterior walls. An oculus above the ablution basin in the central hall was enclosed with a lantern at the time of restoration. A scripture in the mihrab area acknowledges "the work of Masters of Tabriz" on tiles, and the name of Nakkas Ali bin Ilyas Ali appears above the royal box as designer of the entire decorative scheme.
The mosque is built out of sandstone and clad with marble panels, a majority of which was replaced in the nineteenth century. Flower designs and scriptures carved in marble frame the entry and the windows, with a different design featured in tympana of every window. The grand entrance and the mihrab niches on the northern façade are crowned with marble stalactite half-domes. The two minarets are later additions to the building; they have been fitted with stone spires carved in the baroque manner at the time of renovation.
Baykal, Kazim. Bursa ve Anitlari. Türkiye Anit Çevre Turizm Degerlerini Koruma Vakfi: 1982, Istanbul. (Edited reprint of original from 1950).
Goodwin, Godfrey. A History of Ottoman Architecture. Thames and Hudson: London, 1997 (reprint of 1971).
Gabriel, Albert. Une Capitale Turque, Brousse, Bursa. Paris, E. de Boccard, 1958.