"Osman IV (Oldenburg Sweden)"@en . . "He was born on 24 February 1895 in Constantinople, Ottoman Empire, a son of Prince Mehmed Selaheddin Efendi and Jalifer Hanimefendi. He became Sultan of the Ottoman Empire and Caliph of Islam upon the death of his half-brother, Ahmed IV, on 4 June 1954. He reigned until his death on 19 May 1973 in Constantinople and was succeeded by Abdulaziz II."@en . "He was born on 24 February 1895 in Constantinople, Ottoman Empire, a son of Prince Mehmed Selaheddin Efendi and Jalifer Hanimefendi. He became Sultan of the Ottoman Empire and Caliph of Islam upon the death of his half-brother, Ahmed IV, on 4 June 1954. He reigned until his death on 19 May 1973 in Constantinople and was succeeded by Abdulaziz II."@en . . . .