Osman I, also known as Osman Bey or Osman Gazi, was the founder and first Sultan of the Ottoman Empire. He is also referred to as the Ottoman Caliph. Synonyms for Osman I include Osman Gazi Han, Osman bin Ertugrul, Osman Bin Artuq, and Osman Shah. Other titles used to refer to him are Osman Bey, Osman Effendi, and Osman the Great. Osman I was known for his bravery, military skills, and leadership qualities. He conquered several territories in Anatolia, which later formed the basis of the Ottoman Empire. His legacy lives on as the Ottoman Empire paved the way for modern Turkey.