See also Ralf Hartemink's page on Iceland.
This section is by Klaus Ole Kristiansen.
This flag is known from about 1913. State institutions, both civilian and military uses a swallow tail version of the same flag, both on land and at sea.
The arms of The Republic of Iceland is the flag (Azure on a cross argent a cross gules), resting on a plate of basalt and supported by the four mythic protectors of Iceland mentioned in Heimskringla: a bull, a bird, a dragon, and a giant.
The proportions are sligtly different from those of the flag. In both cases, the silver cross is 2/9 of the width of the flag/shield, the red cross half the width of the silver cross, and the blue fields at the hoist/top are square. The blue fields at the fly of the flag are twice as long as those at the hoist, those at the bottom of the shield are 4/3 as long as those at the top.
These arms, though with a royal crown, were adopted when Iceland became an independent kingdom in 1919. The crown was removed when Iceland became a republic in 1944.
From 1903 to 1919 the arms of Iceland were Azure a falcon Argent. This replaced the original arms, used since the 15th century: Gules a stockfish (or split dried cod) Argent crowned with an open crown or.