He succeeded his father Mehmed III in 1603 and became the first Ottoman sultan who reached the throne before attaining his majority. He was of kindly and humane disposition, as he showed by refusing to put to death his brother Mustafa, who eventually succeeded him. He was known for his skills in fencing, horseback riding, and fluency in numerous languages.
In the earlier part of his reign he showed decision and vigour, which were belied by his subsequent conduct. The wars which attended his accession both in Hungary and in Persia terminated unfavourably for the Empire, and her prestige received its first check in the Treaty of Sitvatorok , signed in 1606, whereby the annual tribute paid by Austria was abolished. Georgia and Azerbaijan was ceded to Persia.
Ahmed gave himself up to pleasure during the remainder of his reign, which ended in 1617, and demoralization and corruption became as general throughout the public service as indiscipline in the ranks of the army. The use of tobacco is said to have been introduced in the Empire during his reign. Ahmed I died of typhus in 1617.
Today Ahmed I is remembered mainly for the construction of the Sultan Ahmed Mosque (also known as the Blue Mosque), one of the masterpieces of Islamic architecture. The area in Istanbul around the Mosque is today called Sultanahmet.