Orhan Gazi Mosque was begun
in 1339. The building repaired in 1417 by Bayezid Pasa. This mosque contains
a five-bav porch covered by thxee central domes and flat-topped cross vaults.
A domed vestibule leads one to the domed central hall, which is rectangular.
The dome of the main hall is 8.45 m. in diameter. There are eight fan-shaped
panels of triangles placed beiween tall windows. Raised by two steps from
the hall on the south is the main iwan.
This space is a domed rectangle measuring 9.30
m. by 8.65 m. The elliptical dome of the main iwan measures 13.50 m. at
the centre. The tmnsition is effected by squinches decorated inside with
broken triangular panels. Two more . iwans flank the central iwan. Hence,
the mosque is a cross-axial structure. Side iwans are raised and covered
by domes that rest on arches flanking the rectangular halls of the iwans.
Two more rectangular spaces are placed behveen the side iwans and the porch.
The walls of the Mosque are built of composite brick and stone and are
topped by saw-toothed comices. Tall narrow window opennings with semicircular
arch heads, decorative brick medallions on the walls, and the general character
of the masonry work are indications of Byzantine influence.