Ottoman War Medal with bar "Palestine"
 

The Ottoman War Medal (Turkish: Harp Madalyası), also known as the Gallipoli Star was a military decoration of the Ottoman Empire which was instituted by the Sultan Mehmed Reshad V on 1 March 1915 for gallantry in battle. This decoration was awarded for the duration of World War I to Ottoman and other Central Powers troops, primarily in Ottoman areas of engagement. The award includes a badge and a ribbon.The medal, usually made of nickel-plated brass, is a star-shaped badge.

 

Along with the badge came a ribbon with red and white stripes, which was not to be worn with the medal itself, but was to be looped through the second buttonhole of the tunic when the medal was not being worn. However, these often turn up with the ribbon sewn onto the pin on the back, and it appears that this variation on the mode of wear was done during the war. 

There are also trapezoidal clasps that have been seen, designed to be worn on the ribbon, and bearing the names of various campaigns or theaters of operations during the war.  These campaign clasps had no official status, but their wear seems to have been accepted at the time of the war. The picture shown here is of a clasp with Arabic text of "Palestine".

Source: http://gmic.co.uk/index.php/topic/34522-turkish-ribbon-bars/

 

Here an interesting picture from the recommended book "History of Ottoman Order and Medals" by Mr. Edhem Eldem. The ribbon is from a German soldier, serving with the Ottoman forces.

The ribbons from left to right:

- Prussian Long Service Medal

- Honor Cross of the World War 1914 1918, also known as the Hindenburg Cross

- Ottoman War Medal with bar "Palestine"

- Iron Cross