On the inside, it is decorated with thousands of Iznik tiles and painted floral motifs in predominantly blue colours, which give the mosque its popular name.

The Blue Mosque was included in the UNESCO World Heritage Site list in 1985 under the name of "Historic Areas of Istanbul".

After the Peace of Zsitvatorok, seen as a blow to Ottoman prestige, Sultan Ahmed I decided to build a large mosque in Istanbul in the hope of soliciting God's favour.

The mosque's location was originally occupied by the Hippodrome's bleachers and its imperial box (where the emperor sat when attending events here).

[9] Given the mosque's location, size, and number of minarets, it is probable that Sultan Ahmed intended to create a monument that rivalled or surpassed the Hagia Sophia.

[11][5] This, along with the fact that the empire was under economic stress, aroused the protests of the ulema (Islamic legal scholars), who argued that sultans should only fund the construction of an imperial mosque with spoils of conquest.

During preparatory work in 2013, it was discovered that the mosque's northwest minaret had shifted 5 centimetres (2.0 in) over time, constituting a potential threat to its structural stability.

[19][20] The mosque's architect, Sedefkar Mehmed Agha, synthesized the ideas of his master Sinan, aiming for overwhelming size, majesty and splendor.

[22] Architectural historian Doğan Kuban characterizes Mehmed Agha's style as having a more "sculptural" approach, with more attention brought on the details of the building and a willingness to break up its elements into smaller parts, whereas Sinan had placed more emphasis on rigorous spatial designs with relatively restrained decoration.

[23] Scholar Gülru Necipoğlu states that the mosque demonstrates an emerging trend towards extravagance in the structure and decoration of Ottoman buildings during this time, as evidenced by its size, its profile (including the increased number of minarets), and its lavish use of Iznik tiles.

The transitions between the smaller exedrae and the supporting walls or arches are covered by muqarnas (stalactite-like sculpting) made of stucco.

[27] By employing these elements, Mehmed Agha created a softer progression from the rectangular outer walls to the round central dome.

At ground level, the focus of the prayer hall is the mihrab, which is made of finely carved marble, with a muqarnas niche and a two inscription panels above it.

To the right of the mihrab is the richly decorated minbar, or pulpit, where the imam stands when he is delivering his sermon at the time of noon prayer on Fridays or on holy days.

[26] According to Evliya Çelebi, who saw the mosque in the 17th century, a hundred Qur'ans on lecterns inlaid with mother-of-pearl, all gifted by sultans and viziers, were placed near the mihrab.

[32] The loge is reached from the outside via an "imperial pavilion", a large L-shaped structure composed of a covered ramp leading up to two rooms where the sultan could retire to rest, along with an enclosed portico or balcony on the south side overlooking the sea.

[32][verification needed] This auxiliary structure, which is awkwardly integrated into the overall mosque design, is an innovation that appears here for the first time in Ottoman architecture.

[15] The lower walls of the mosque, especially around the galleries, are covered in Iznik tiles, a style of tilework named after their main production center, İznik (ancient Nicaea).

Some panels were designed specifically for the mosque, while others seem to have been reused from other buildings and amassed here, including lower-quality tiles added during later repairs.

[34] The predominant colour of this paintwork is blue, one of the reasons for the mosque's popular name, though much of it has since been replaced with modern imitations of the original 16th/17th-century style.

[34] The mosque also contains some original inlaid woodwork of high quality, including the doors of the courtyard entrance, which were made by the father of Evliya Çelebi.

This approach differs slightly from that of Sinan and earlier Ottoman architects, who used the deliberate juxtaposition of curved domes and vertical elements to create a more dramatic effect.

[42][13] From the courtyard, the prayer hall is also entered via a monumental gate on the southeast side, decorated with its own muqarnas semi-vault and inscription panel.

[13] On the inside, the mosque courtyard has a classic rectangular peristyle form, lined on each side with an arcaded and domed portico (or riwaq).

[45] Historically, the muezzin had to climb a narrow spiral staircase inside the minarets five times a day to announce the call to prayer.

[44][dead link‍] As in most major Ottoman religious foundations, the Sultan Ahmed Mosque is the main element of a larger complex of buildings.

[15] Unlike many Ottoman mausoleums, which most typically have an octagonal form, the tomb chamber has a square floor plan covered by a dome, more reminiscent of a small mosque.

[47][13] The main features that depart from the design of earlier madrasas are the lack of a monumental entrance portal and the placement of the dershane (a larger domed chamber serving as a classroom), which is attached to a corner of the building rather than placed in the middle of one side.

[47] A separate square structure, the darülkurra (a school that teaches reading of the Qur'an), is contained within the outer enclosure of the nearby mausoleum It was restored in 1935 and is currently used as a storage for Ottoman archives.

[13] The primary school (sibyan mektebi) is a small and simple rectangular structure built over the outer precinct wall on the east side of the mosque.