Osman I Summary Osman I or Osman Ghazi was the first caliph and founder of the Ottoman Empire. who spent his whole life building the Ottoman Empire to fulfill the wish of his father Ertugrul Ghazi. In 656 AH, about 1258 AD, under the command of Halagu Khan, Mongolians attacked Baghdad, the capital of Abbasid’s Caliphate. Muslims […] http://alishaa.free.nf/