Hejaz

Existed: 10 June 1916 - 22 September 1932
Status: Independent nation
Capital: Mecca
Where: Arabian Peninsula
Now: Incorporated into Saudi Arabia

Hejaz was part of the Ottoman Empire from August 1517 until 10th June 1916 when it declared its independence as the Hejazi Kingdom.
In 1917, Hejaz gave the Farasan Islands to 'Asir in exchange for al-Qunfudhah.
On 10th August 1920, its independence was recognised with the signing of the Treaty of Sèvres.
On 19th December 1925, Hejaz was occupied by Nejd.
On 8th January 1926, Hejaz was unofficially annexed by Nejd.
On 20th November 1930, 'Asir was incorporated into Hejaz.
On 22nd September 1932, Nejd and Hejaz were unified as the Kingdom of Saudi Arabia.

The flag above has been taken from Roberto Breschi's Bandiere website at http://www.rbvex.it/index.html.