The Yıldırım Beyazıt Mosque was built in the last decade of the 14th century, together with the other buildings of the complex: medrese (school), darüşşifa (hospital), aşhane (soup kitchen), misafirhane (hostel), a small hamam (bath), and the sultan’s türbe (mausoleum). The mosque-annex-hostel was restored in 1879.

It was the first mosque in Bursa to have an open gallery at its northern side, which is covered by five small cupolas, resting on six pillars. The ground plan of the mosque shows, how the early-Ottoman mosque is the continuation of the late-Seljuk (covered) medrese: a small entrance hall (in the north) opens into a square inner courtyard under a dome (11½ m diameter, 22½ m height). This central space is surrounded by three large ‘iwan’-rooms (in the west, south and east) forming the three branches of an ‘inversed T’. The iwan in the south is raised
(some 70 cm) and is called ‘mihrab eyvanı’ (iwan-room of the prayer niche); in the original functioning of the building, this square space (12 x 12 m) was the prayer hall; the domed inner courtyard and the western and eastern iwans functioned as a meeting area, which could be filled by the congregation during common prayer (as all mosque’s yard – or even the street in front of the mosque – can be). Adjacent to the T-shaped inner space of the building, there are four rooms in the corners of the building; they form the ‘misafirhane’ (hostel), where guests could stay.

On the picture: The ‘mihrab eyvanı’ and its classic Ottoman decoration in 16th-18th century styles.

An iwan (Persian & Turkish: ‘eyvān’) is a rectangular hall or space, usually vaulted , walled on three sides, with one end entirely open. This architectural form can be used for entrances, but also to create half open rooms looking out at a central yard. The iwan as used in Anatolian Seljuk ‘medrese’ was imported from Islamic Persia, but was invented much earlier and fully developed in Mesopotamia.
In early-Ottoman architecture, the iwan principle was used also, but the rooms were no longer vaulted, but covered by a dome.

Correspondent: J.M.Criel, Antwerpen.
Sources: ‘Vakıf Abideler ve eski Eserler’ - Vakıflar Genel Müdürlüğü III, Ankara 1983
& Website of ‘mimarlikmüzesi.org’