This mosque was commissioned jointly by the grand vizier Sokollu Mehmed Pasha and his wife Esmahan Sultan, who was a daughter of Sultan Selim II and a granddaughter of Suleiman the Magnificent. She was, in other words, Ottoman royalty — and her husband was the man who ran the empire. Together they endowed this foundation in the Kadırga neighborhood of the Fatih district, on the European shore of the old city, not far from the Sea of Marmara. The architect was Mimar Sinan, imperial architect to three sultans. According to the foundation inscription in Turkish above the north entrance to the courtyard, the building was completed in AH 979, which corresponds to 1571 or 1572 CE. There is a quiet complexity in that inscription: although Esmahan Sultan and her husband jointly funded and commissioned the mosque, only Sokollu Mehmed Pasha's name appears in the official record. Her contribution was real; the credit was his.

The site in Kadırga presented Sinan with a challenge that would have stumped a lesser architect: a steep slope that made a standard mosque footprint impossible. His answer was to make the difficulty invisible. He fronted the mosque with a two-storey courtyard that absorbed the grade change. The lower level he divided into shops, their rents funding the mosque's upkeep in perpetuity. The upper level he opened into a colonnaded courtyard, walling off spaces between columns on three sides to create small rooms — each fitted with a window, a fireplace, and a niche for bedding — that served as student cells for the attached religious school, or madrasah. The mosque itself occupies the fourth side of the courtyard, designed as a hexagon inscribed in a rectangle. Its central dome, thirteen meters in diameter and nearly twenty-three meters high, is flanked by four small semi-domes at the corners. The ablution fountain at the courtyard's center has twelve columns supporting an onion-shaped dome. A single minaret rises from the northeast corner. The whole complex makes no concession to the difficult terrain. It simply conquers it.

The fame of the Kadırga Sokollu mosque rests above all on its İznik tiles. Produced in the city of İznik during the peak period of Ottoman ceramic production, they cover the interior walls in cascading panels of blue, red, and green floral designs. White thuluth calligraphy on a blue ground forms bands of Quranic inscription. The columns inside are polychrome marble. The minbar — the pulpit from which the sermon is delivered — is white marble with a conical cap, sheathed entirely in İznik tile. The windows above the mihrab glow with stained glass. Some of the original painted decoration survives above the vestibule of the north entrance, on the brackets of the entrance balcony, and under the ceilings of the side galleries. Standing inside, with light falling through stained glass onto the tilework, and the three fragments of the Black Stone set into their appointed places above mihrab, minbar, and door, the interior achieves something precise: it is intimate and overwhelming at once.

The Black Stone (al-Hajar al-Aswad) at the Kaaba in Mecca is the most venerated object in Islam. Pilgrims on the Hajj circumambulate the Kaaba and, if they can, touch or kiss the Stone. That three fragments of this stone were embedded in the walls of a mosque in Istanbul — above the main entrance, above the pulpit, above the prayer niche — transforms the building into something more than an act of architectural patronage. It makes it a site of connection to Mecca itself, a physical extension of the sacred toward the faithful. The fragments are set in their gilded bezels with care, each one positioned to be seen and contemplated. They remain in place today, four and a half centuries after the building was completed. The mosque is still active, still visited by worshippers and pilgrims, its tiles still shining in the filtered light of a Kadırga afternoon.