Which National Flags Are Square?

The overwhelming majority of national flags use a ratio of 2:3 (twice as wide as tall) or 1:2. A handful use 3:5, 5:8 or 4:7. But two countries fly a 1:1 square, and their reasons are historical.

Switzerland

The Swiss flag is a bold white couped cross on a square red field. The square shape descends from the battle flags carried by the medieval Swiss Confederation's cantonal contingents, which were square, and it was fixed by federal law in the 19th century. Switzerland's civil ensign, flown on ships and boats, is the same design in a normal 2:3 rectangle, so a square Swiss flag on a mast means the state flag, while a rectangular one at sea is the merchant ensign. The flag of the International Committee of the Red Cross — founded in Geneva — is a deliberate colour-reversal of the Swiss flag, and it too can be seen in square form.

Vatican City

The Vatican's flag is a square divided vertically into yellow (hoist) and white (fly), with the papal tiara and the crossed keys of Saint Peter on the white half. It was adopted in 1929 when the Lateran Treaty created the modern Vatican City State, and the square shape matches Switzerland's — fittingly, since the Pope's ceremonial guard is the Swiss Guard. The gold and white are the traditional colours of the Holy See; gold recalls the golden key, white the silver key.

The near-misses

• Nepal is not square, but it is the only non-rectangular national flag — two stacked triangles forming a double pennon. Its overall shape is taller than it is wide.
• Belgium's flag is officially a 13:15 ratio, unusually close to square for a tricolour, though it is almost always flown as a normal rectangle.
• Many subnational flags are square (several Swiss cantons, some German and Italian regions), but they are not national flags.