Which Ottoman sultan commissioned the Blue Mosque in Istanbul? Ahmed I commissioned it. The mosque is formally called the Sultan Ahmed Mosque, after the ruler who ordered its construction.
Construction began in 1609 and the mosque opened around 1616–1617. Ahmed wanted a monumental imperial mosque near Hagia Sophia and the old Byzantine Hippodrome, creating a landmark that could rival the city’s most famous former cathedral. The complex included educational, charitable, and public facilities alongside the mosque itself.
The project was controversial because Ahmed had not won a major military conquest whose spoils could fund it. Instead, money came from the treasury, prompting objections from religious scholars. Its six minarets also caused controversy because the Masjid al-Haram in Mecca had the same number; Ahmed resolved this by funding a seventh minaret for Mecca.
The mosque is called “Blue Mosque” because of its extensive blue İznik tilework, although that is not its official name. Ahmed I died in 1617 and was buried in a mausoleum beside the mosque.