The design of the Sultan Ahmed Mosque is the culmination of two centuries of both Ottoman mosque and Byzantine church development. It incorporates some Byzantine elements of the neighboring Aya Sophia with traditional Islamic architecture and is considered to be the last great mosque of the classical period. The architect has ably synthesized the ideas of his master Sinan, aiming for overwhelming size, majesty and splendour. It has one main dome, six minarets, and other eight secondary domes.

The facade of the spacious forecourt was built in the same manner as the facade of the Süleymaniye Mosque, except for the addition of the turrets on the corner domes. The court is about as large as the mosque itself and is surrounded by a continuous vaulted arcade. It has ablution facilities on both sides. The central hexagonal fountain is rather small in contrast with the dimensions of the courtyard. The monumental but narrow gateway to the courtyard stands out architecturally from the arcade. Its semi-dome has a fine stalactite structure, crowned by a small ribbed dome on a tall tholobate.

A heavy iron chain hangs in the upper part of the court entrance on the western side. Only the sultan was allowed to enter the court of the mosque on horseback. The chain was put there, so that the sultan had to lower his head every time he entered the court in order not to get hit. This was done as a symbolic gesture, to ensure the humility of the ruler in the face of the divine.

The six minarets were a matter of contention and a first, since four minarets were the common maximum. Only after one more minaret was added to the Masjid al-Haram, Grand Mosque, in Mecca was the six minarets issue settled.

At its lower levels and at every pier, the interior of the mosque is lined with more than 20,000 handmade ceramic tiles, made at Iznik (the ancient Nicaea) in more than fifty different tulip designs. The tiles at lower levels are traditional in design, while at gallery level their design becomes flamboyant with representations of flowers, fruit and cypresses. More than 20,000 tiles were made under the supervision of the Iznik master potter Kasap Haci and Baris Efendi from Avanos (Cappadocia). The price to be paid for each tile was fixed by the sultan's decree, while tile prices in general increased over time. As a result, the quality of the tiles used in the building decreased gradually. Their colours have faded and changed (red turning into brown and green into blue, mottled whites) and the glazes have dulled. The tiles on the back balcony wall are recycled tiles from the harem in the Topkapı Palace, when it was damaged by fire in 1574.

The upper levels of the interior are dominated by blue paint. More than 200 stained glass windows with intricate designs admit natural light, today assisted by chandeliers. On the chandeliers, ostrich eggs are found that were meant to avoid cobwebs inside the mosque by repelling spiders. The decorations include verses from the Qur'an, many of them made by Seyyid Kasim Gubari, regarded as the greatest calligrapher of his time. The floors are covered with carpets, which are donated by faithful people and are regularly replaced as they wear out. The many spacious windows confer a spacious impression. The casements at floor level are decorated with opus sectile. Each exedra has five windows, some of which are blind. Each semi-dome has 14 windows and the central dome 28 (four of which are blind). The coloured glass for the windows was a gift of the Signoria of Venice to the sultan. Most of these coloured windows have by now been replaced by modern versions with little or no artistic merit.

The most important element in the interior of the mosque is the mihrab, which is made of finely carved and sculptured marble, with a stalactite niche and a double inscriptive panel above it. The adjacent walls are sheathed in ceramic tiles. But the many windows around it make it look less spectacular. To the right of the mihrab is the richly decorated minber, or pulpit, where the Imam stands when he is delivering his sermon at the time of noon prayer on Fridays or on holy days. The mosque has been designed so that even when it is at its most crowded, everyone in the mosque can see and hear the Imam.

The royal kiosk is situated at the south-east corner. It comprises a platform, a loggia and two small retiring rooms. It gives access to the royal loge in the south-east upper gallery of the mosque. These retiring rooms became the headquarters of the Grand Vizier during the suppression of the rebellious Janissary Corps in 1826. The royal loge (hünkâr mahfil) is supported by ten marble columns. It has its own mihrab, that used to be decorated with a jade rose and gilt and one hundred Qurans on inlaid and gilded lecterns.

The many lamps inside the mosque were once covered with gold and gems. Among the glass bowls one could find ostrich eggs and crystal balls. All these decorations have been removed or pillaged for museums.

The Minarets of the Blue Mosque

The Blue Mosque is the first six-minaret mosque in Turkey. The legend has that when the construction of the mosque starts, the sultan of the period, The Sultan Ahmet I, orders the architect Sedefkar Mehmet to make the minarets from gold.

However, it is later understood that using gold on the minarets would increase the sultan’s budget to an amount more than planned. As a result the architect Sedefkar Mehmet constructed the mosque not with gold but with six minarets.

The Sultan Ahmet I then asks the architect why he did not use gold and why he built six minarets. The architects trying not to upset the sultan acts as if he misunderstood his order and says: “Your Excellency, but you ordered to build the mosque with six minarets and I did so”.

Note: Here is a word trick. Gold means “altın” and six means “altı” in Turkish. The architect acts as if he mistook the word “altın” with the word “altı”.