Every sultan of the Ottoman Empire had his own monogram, called the tughra, which served as a coat of arms. A modern coat of arms, (inspired by the European heraldic tradition) was created in the late 19th century. The final design was adopted by Sultan Abdul Hamid II on April 17, 1882. It included two flags: the flag of the Osmanli Dynasty which had a crescent and a star on red base and the flag of the Islamic Caliph which had 3 crescents on a green base.
Some graphic elements of the coat of arms of the Ottoman Empire such as the central oval and the vertically-oriented crescent and star were re-edited in the current semi-official emblem of the Republic of Turkey.