The former name of France (Gaul) was homonymous in Latin, with the species "Gallus" (the hen and rooster family). In some periods of French history, the rooster as the emblem of the ancestors of the French came back in favour, partly due to nostalgy, partly due to the rejection of monarchic emblems. That was the case under the French Revolution and at the end of the 19th Century, when French history was revisited.
In addition France was a Catholic country, and the rooster was also a Catholic symbol, figuring in the story of St Peter in the Bible; also crowing for the day, it announces the return of the day, as in the resurrection.
Fleur de Lys
the rooster ('le coq gaulois')
French symbols are signs that relate to France like the national emblem.
The Unknown Soldier of France World War I. By virtue of an act of Congress approved 4 March 1921, the Medal of Honor, emblem of the highest ideals
According to the French constitution, there is only one official emblem, which is the French flag (blue, white and red). However, the Gallic Rooster is used as an unofficial symbol for France.