Osman IV (December 18, 1898 - June 8, 1983) was the Sultan of the Turkish Empire between March 14th, 1923 and May 8th, 1983, thus making his reign over sixty years - the longest reign of any monarch during the 20th century. During his reign, Osman IV was noted for his investment in Turkish infrastructure, his continuation of his father Selim V's attempts to make the Sultanate the secular organ of the state, his expansion of rights in non-Turkish territories of the Empire (in particular the Balkans) and his rebuilding of Turkey as a preeminent world power.