Did you know “Ottoman” is a corruption of the Turkish/Persian/Urdu “Osman”, their version of the Arabic “‘Uthman”? The “th” in Arabic becomes “s” in Persian, Urdu, and Turkish pronunciation systems. Interesting that the Europeans would grab “Osman” and transform it into something that better resembles the Arabic origin.
The Turks used “Osman” (actually “Osmanlı”, meaning “people of Osman”) in reference to the founder of their ruling dynasty, Osman Gazi or Osman, son of Ertuğrul. The Ottoman Turks overthrew the Seljuk Turks, so they were by no means the first Turkish imperial power.