Rio de Oro

Rio de Oro was a Spanish colony, the southern part of what is now the disputed Western Sahara today.

 File:Rio de Oro 1905.jpg|1905 25c value File:Rio de Oro 1907.jpg|1907 2c value File:Rio de Oro 1908 surch.jpg|1907 "2 CENS" on 2p surcharge. File:Rio de Oro revenue ovptd.jpg|1908 5c on 50c Spanish West Africa revenue File:Rio de Oro HAB.jpg|1908 15c on 1p surcharge in violet File:Rio de Oro star crnr.A.webp|1909 10c definitive. File:Rio de Oro 1910 surch.jpg|1910 10c on 4p surcharge 
 * Beginning in 1901, Spanish stamps were used in Rio de Oro, identifiable by cancels. These were only used until the colony issued its own stamps.
 * In 1905, a series with the portrait of the young Alfonso XIII was issued. It was inscribed COLONIA DE RIO DE ORO.
 * In 1907, the 25c value was surcharged HABILITADO / PARA / 15 CENTS in an oval. This style would be re-used on other values in 1908.
 * In 1907 and 1908, surcharges with the year date and new value were released.
 * Also in 1907, new definitives with Alfonso XIII in uniform were issued.
 * In 1908, large Spanish West Africa revenues were overprinted HABILITADO / PARA / CORREOS with RIO DE ORO and the new value at the sides.
 * In 1909, new definitives with a curved banner at bottom were issued. Denominations are given in 8-pointed stars in the upper corners.
 * In 1910, surcharges on the first definitives were issued with "1910" and new values.
 * In 1911-13, surcharges on the second definitives were issued, with new values denominated "Cens" or "Céntimes".
 * In 1912, definitives with Alfonso XIII facing to the left and a curved banner at top were released.

 File:Rio de Oro 1916.jpg|1912 5c definitive File:Rio de Oro 1914.jpg|1914 2c value File:Rio de Oro 1917.jpg|1917 20c value File:Rio de Oro 1919.jpg|1919 4p value File:Rio de Oro 1921-2.A.webp|1922 10c value 
 * In 1912, new designs with a curved banner at top were issued.
 * In 1914, new definitives were issued with the denominations in corner tablets at the the top and 1914 at bottom.
 * In 1917, stamps from 1912 were overprinted 1917, probably because they could.
 * In 1919, new definitives appeared (magically?) with a large tablet at bottom reading COLONIA / DE RIO DE ORO.
 * In 1920, once again, new designs were issued with a smaller portrait facing left, with AÑO and 1920' in the upper corners.
 * In 1922, new designs followed (could you guess?) with Alfonso XIII facing right again, AÑOS and 1921-22 in the upper corners.
 * In 1924, Rio de Oro became part of Spanish Sahara.