The flag of Turkey is a red flag with a white crescent moon and a star in its centre.
The flag has a complex origin since it is an ancient design, and uses the same symbols of the late flag of the Ottoman Empire which was adopted in 1844 with the Tanzimat reforms; though the shape, placement and shade of the color varies. The geometric proportions of the flag were legally standardized with the Turkish Flag Law in 1936.
The current design of the Turkish flag is directly derived from the late Ottoman flag, which had acquired its final form in 1844. It is known that the Ottomans used red flags of triangular shape at least since 1383, which came to be rectangular over the course of history.
Ottomans used several different designs, most of them featuring one or more crescents, for different purposes, such as the flag with green background signifying the caliphate. During the late imperial period, the distinctive use of the color red for secular and green for religious institutions became an established practice. In 1844, the eight-pointed star was replaced with a five-pointed star and the flag reached the form of the present Turkish flag; Red was the colour of Umar I, the Caliph who ruled from AD 634 to 644 and was known as a great consolidator of the Islamic Empire. In the 14th century red became the colour of the Ottoman Empire. The crescent and star is the symbol of Turks.
The origin of the flag is the subject of various legends in the country, some contradicting the historical knowledge about the Ottoman Flag.