The Liechtenstein flag is rectangular, with a ratio of length to width of 5:3. The flag is made up of two parallel rectangles, blue and red, with a golden crown in the upper left corner. Liechtenstein is a hereditary constitutional monarchy. Blue and red on the flag come from the color of the prince's flag. Blue symbolizes the blue sky and red symbolizes the fire on the ground at night. The crown on the flag is the crown of the Holy Roman Empire, which was added in 1937 to distinguish it from the Haitian flag. The crown is also a symbol of the Holy Roman Empire, because Liechtenstein was historically the fiefdom of the Holy Roman Empire's princes.