After the Peace of Zsitvatorok and the unfavourable result of the wars with Persia, Sultan Ahmed I decided to build a large mosque in Istanbul to placate Allah. This would be the first imperial mosque in more than forty years. Whereas his predecessors had paid for their mosques with their war booty, Sultan Ahmed I had to withdraw the funds from the treasury, because he had not won any notable victories. This provoked the anger of the ulema, the Muslim legal scholars.

The mosque was to be built on the site of the palace of the Byzantine emperors, facing the Hagia Sophia (at that time the most venerated mosque in Istanbul) and the hippodrome, a site of great symbolic significance. Large parts of the southern side of the mosque rest on the foundations, the vaults and the undercrofts of the Great Palace. Several palaces, already built on the same spot, had to be bought (at considerable price) and pulled down, especially the palace of Sokollu Mehmet Pasa, and large parts of the Sphendone (curved tribune with U-shaped structure of the hippodrome).

Construction of the mosque started in August 1609 when the sultan himself came to break the first sod. It was his intention that this would become the first mosque of his empire. He appointed his royal architect Sedefhar Mehmet Aga, a pupil and senior assistant of the famous architect Sinan as the architect in charge of the construction. The organization of the work was described in meticulous detail in eight volumes, now in the library of the Topkapi Palace. The opening ceremonies were held in 1617 (although the gate of the mosque records 1616) and the sultan was able to pray in the royal box (hunkâr mahfil). The building was not yet finished in this last year of his reign, as the last accounts were signed by his successor Mustafa I. Known as the Blue Mosque, Sultan Ahmet Mosque is one of the most impressive monuments in the world. It is one of the elements included in the complex built by Ahmed I to compete with Ayasofya.

View of the inner courtyard 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 Hagia 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, but the interior lacks his creative thinking. During the rule of Ahmed I, Sultan Ahmet mosque was built between 1609 and 1616 CE. Designed by architect Sedefkar Mehmet Aga, the Sultan Ahmet Mosque is considered to be the last example of classical Ottoman architecture.

The Sultan Ahmed Mosque is one of the two mosques in Turkey that has six minarets, the other is in Adana. When the number of minarets was revealed, the Sultan was criticized for presumption, since this was, at the time, the same number as at the mosque of the Kaaba in Mecca. He overcame this problem by paying for a seventh minaret at the Mecca mosque.
Four minarets stand at the corners of the mosque. Each of these fluted, pencil-shaped minarets has three balconies (Serefe) with stalactite corbels, while the two others at the end of the forecourt only have two balconies.
Until recently the muezzin or prayer-caller had to climb a narrow spiral staircase five times a day to announce the call to prayer. Today a public address system is used, and the call can be heard across the old part of the city, echoed by other mosques in the vicinity. Large crowds of both Turks and tourists gather at sunset in the park facing the mosque to hear the call to evening prayers, as the sun sets and the mosque is brilliantly illuminated by coloured floodlights.