The Gallic Rooster or coq gaulois is a symbol of the French nation and history, in addition to its land and culture. Along with Marianne of France and the lily, the Gallic Rooster symbolizes France and the French people, and he often appears on official seals. The Gallic Rooster also represents France in international sporting events, acting as the mascot for many French sports teams and sometimes even marching in the opening ceremonies of the Olympics.
Roosters have played a role in the symoblism and folklore of many nations for thousands of years. For many people, the rooster symbolizes bravery and boldness as he defends the flock against all comers, along with virility. In France, roosters were often used to decorate church bells and watchtowers, since the rooster symbolizes vigilance, as he wakes at dawn to alert people to the start of the day. During the French Revolution, the rooster often appeared in art, symbolizing hope and faith, and well through the 1800s, the Gallic Rooster appeared on French coins.
If you know Latin, you may be aware that the “Gallic Rooster” is also a play on words. The Latin word gallus means rooster (it's the root word behind the Spanish gallo as well), and it can also be used to refer to a citizen of Gaul, now known as France. This play on words was well known in Roman times, when many Gauls used roosters to symbolize their loyalty to Gaul.
This French national emblem appears in all sorts of places. Some French homes, for example, have rooster doorknockers, while many French businesses use roosters in their logos or to decorate their signs. The Gallic Rooster also appears in some government seals and logos, along with other symbols of France, and many French farmyards have a Gallic Rooster of their own. The French resistance also used this symbol during the Second World War, to remind themselves of the resilience and bravery of the French people, urging the French to resist occupation.