Osman I or Osman Ghazi (Ottoman Turkish: عثمان غازى, romanized: ʿOsmān Ġāzī; Turkish: I. Osman or Osman Gazi; died 1323/4) was the founder of the Ottoman Empire (first known as the Ottoman Beylik or Emirate). While initially a small Turkoman principality during Osman's lifetime, his beylik transformed into a vast empire in the centuries after his death. It existed until 1922 shortly after the end of World War I, when the sultanate was abolished.