The mosque is part of a kulliye ordered by Zal Mahmud Pasha, one of the viziers of Selim II. The complex is masterfully planned on a sloping site, with two separate levels linked bya flight of stairs. Themosque and a medrese are situated on the higher level, while the lower part consists of another medrese and a tomb. The com- position is more organic than symmetric. Due to the slope, the mosque has a vaulted basement It also has a beautiful view over the Golden Horn.
With this mosque, Sinan tried out effects quite opposite to the ones observed in usual mosque designs. Wide galleries situated on three sides reach as high as the arches carrying the dome. While in most of Sinan’s mosques the main arches are filled in with a windowed wall or topped with a semidome, here, except for the kiblah (southern) wall, the arches stand naked, opening onto the galleries. This weakens the effect of the dome, the on space widening on three sides, while the thickness of the arches, unhidden by a windowed wall, is left apparent. Indeed, the galleries, spreading as far in as to reach the arches and reaching the height of their springing line, cause the dome to lose some of the effect of its height and it seems to lower itself closer to human reach.
Contrary to the case of the Edirnekapi Mihrimah Mosque, the roofs of the galleries are high enough to reach up to the drum of the dome. With the light coming through the three rows of numerous windows of the outer walls, the upper galleries especially turn out to be better lit than the middle ground. This is very different from the usual contrast, where the central area receives more light than the sides. On the kiblah (Mecca facing) front, the main arches are hidden in the wall, while they stand on two rounded piers on the entrance side. The southern wall looks like a partition wall pierced with windows all the way to the ground, while on the other side, the arch piers are covered with the galleries. As a result, the dome seems to be hanging in space. Together with its basement floor, the mosque rises on three sides like some lofty prismatic structure. We do not find here the pyramidal effect seen in Sinan’s grand mosques.
In order to diminish the weight of the mosque’s whole mass, the side walls especially have been pierced with numerous windows, which gives them a quasi-palatial aspect, while the facades are made of alternate rows of stone and brick. In spite of its few contradictions, the Zal Mahmud Mosque remains a highly original experiment that owes nothing to previous schemes.