This is Sinan's second semidomed attempt, and corresponds to the last stage
in the development of this type of structure. Indeed, with its four semidomes,
the mosque has a fully matured centralised plan. The scheme is both an improved
version of the Mihrimah Mosque in Uskudar and a reinterpretation of the old
model of the Fatih (1471) and Beyazit (1506) Mosques. This plan had also been
implemented at the Fatih Pasha Mosque (1522) in Diyarbakir and the Ulu (Grand)
Mosque (end of the 15th century) in Elbistan. It is basically a square, with the
space spreading around a vertical axis. The dominance of the central dome is
felt as soon as one enters the mosque. Indeed, the modest size of the piers
carrying the dome and the absence of columns to isolate the lateral galleries
facilitate the perception of the central area in its entirety.
From the outside, the whole mass of the mosque appears structured like a
pyramid. The porticoes on the two side walls are innovations which happily
herald future developments. They soften the building's flanks, and blend
perfectly into the entrance facade giving them all a more human proportion
as well as an increased functionality. The main function of these porticoes is
to hide the buttresses. It is quite striking that, after designing only a few
mosques, Sinan should succeed to produce such a bold and at the same time mature
work. Here, despite his general preference for greater simplicity, Sinan has
created his most decorated building, perhaps because it was designed in memory
of the death of a very young prince. The plan of the sehzade Mosque met with
great success, and served as a model for large mosques built after Sinan such as
the Yeni Valide Mosque (1597-1663), the Sultan Ahmet (Blue) Mosque, (1609) as
well as the Yeni (New) Fatih Mosque (1667-1771).
Above text and pictures are from the book titled "Turkish Art and Architecture in Anatolia and Mimar Sinan".
You can purchase "Turkish Art and Architecture in Anatolia and Mimar Sinan" book and other Turkey related books from Explore Turkey Bookstore.