The Flag of the United Mexican States or Mexico is a vertical tricolor of green, white, and red with the national coat of arms charged in the center of the white stripe. While the meaning of the colors has changed over time, these three colors were adopted by Mexico following independence from Spain during the country's War of Independence. The current flag was adopted in 1968, but the overall design has been used since 1821, when the First National Flag was created. The current law of national symbols, Law on the National Arms, Flag, and Anthem, that governs the use of the national flag has been in place since 1984. France was the inspiration of those who detached Mexico from Spain in 1821, and they devised a new tricolor based on the flag of the liberation army. At that time the Italian tricolor was not in use. The flag now contains the coat of arms, in order to distinguish it from that of Italy. Red, white, and green are the colors of the national liberation army in Mexico. The central emblem is the Aztec pictogram for Tenochtitlan (now Mexico City), the center of their empire. It recalls the legend that inspired the Aztecs to settle on what was originally a lake-island. The form of the coat of arms was most recently revised in 1968. Aztec legend held that they should found their city on the spot where they saw an eagle on a cactus, eating a snake. Ribbon in the national colors at are the bottom of the coat of arms. Throughout history, the flag has changed 4 times, as the design of the coat of arms and the length-width ratios of the flag have been modified.