Who was the longest serving Ottoman sultan?

Suleiman I: The Longest-Serving Sultan

Suleiman I, referred to as “the Magnificent” in the Western world and known as “Kanuni” (the Lawgiver) in Eastern cultures, lived from November 6, 1494 until September 7, 1566. He was the tenth Sultan of the Ottoman Empire and held the throne for the longest period, reigning from 1520 until his death in 1566 (Wikipedia).