The Mexican flag consists of a rectangle divided in three equal vertical bands with the colours in the following order, beginning from the left: green, white and red. In the central white band is the national emblem.

The story of the colours of the Mexican flag comes from the time of the War of Independence with Spain (1810 to 1821). Originally, there were several different Mexican groups fighting for the creation of a new nation. When the these groups came to an agreement and formed the Army of the Three Guarantees, they decided on an independent monarchy, one religion, and the union of all Mexican people.

Therefore the colours are:

• Green for independence
• White for religion
• Red for union  

The national emblem is an eagle holding a snake in its beak. The eagle stands on a nopal cactus plant. The emblem dates back to the time of the Aztecs coming to the Valley of Mexico, and is based on the legend of the founding of the Aztec capital, Tenochtitlan.