The Mexican Flag is a red, white and green banner whose center contains an eagle eating a rattlesnake while standing with its left claw upon a nopal cactus, and a half circle of green oak (enciño) on the left (symbolizing strength) and laurel branches on the right (symbolizing victory). The red symbolizes the blood that was shed during the battles for Independence. The white symbolizes purity. The green symbolizes the fertility of the earth.
The eagle eating a snake while perched upon a cactus is from an ancient Aztec legend in which the Aztec people were told by Huitzilopochtli (their God) that to find their promised land, they were to find the place where an eagle landed on a nopal cactus while eating a snake. After wandering for hundreds of years, they found the eagle on a small swampy island in Lake Texcoco. This new Aztec home was named Tenochtitlan (meaning "Place of the Nopal Cactus"), and in 1325, they built what is now called Mexico City.
This flag was first used on September 17, 1968 (it was decreed by Gustavo Díaz Ordaz); it was a variation on a flag first used in 1821.
