Ahmed I, Ottoman Emperor (died 1617)

Ahmed I was the sultan of the Ottoman Empire from 1603 to 1617. Ahmed's reign is noteworthy for marking the first breach in the Ottoman tradition of royal fratricide; henceforth, Ottoman rulers would no longer systematically execute their brothers upon accession to the throne. He is also well known for his construction of the Blue Mosque, one of the most famous mosques in Turkey.

The sultans of the Ottoman Empire, who were all members of the Ottoman dynasty, ruled over the transcontinental empire from its perceived inception in 1299 to its dissolution in 1922. At its height, the Ottoman Empire spanned an area from Hungary in the north to Yemen in the south and from Algeria in the west to Iraq in the east. Administered at first from the city of Söğüt since before 1280 and then from the city of Bursa since 1323 or 1324, the empire's capital was moved to Adrianople in 1363 following its conquest by Murad I and then to Constantinople in 1453 following its conquest by Mehmed II.

April 18 is the 108th day of the year in the Gregorian calendar; 257 days remain until the end of the year.