The flag ofis a very old flag in Mexico's flags history. It is a rectangle divided in two diagonal stripes, one in color red and the other one in white. This flag has had a relevant place in the State of Tlaxcala (in the murals of State Hall), the arms, which was given in 1535 (being the first indigenous city to recieve one by the Spanish Kingdom) consists on a "French style" green-bordered red shield. It bears a yellow castle resembling Castile (Spain) whose flag over the main tower shows the Austrian arms. Over the border, at the top corners there are two golden initials "I" and "F" for the of Spain, Isabel (Elizabeth) and Fernando (Ferdinand) respectively; between them the letter "K", also golden, for Karolus (Charles I of Spain and V of Germany) who granted to Tlaxcala such arms; in both side two leaves, and in the bottom two skulls and two crossed bones.
The ratio of width to length of the flag is 3:5.