Crosses in heraldry Crowns. Several national flags are based on late medieval war flags, including the white-on-red crosses of the flag of Denmark and the flag of Switzerland. The elongated Nordic cross originates in the 18th century due to the rectangular shape of maritime flags. The Red Cross flag originates in 1906 as a colour-switched version of the flag of Switzerland. Crosses in heraldry The cross is a basic design of two intersecting lines (X) used from pre-historic times. Its use was enormously expanded as the Christian cross, from about the 6th century, deriving from a T-shape representing the gibbet ("stauros", "crux") of
Flag of Switzerland squares until 1889, when its dimensions were officially set. The civil and state ensign of Switzerland, used by Swiss ships, boats and non-governmental bodies, is rectangular in shape and has the more common proportions of 3:2. The Swiss flag is one of only two square sovereign-state flags, the other being the flag of Vatican City. The emblem of the Red Cross is the Swiss flag with switched colours. According to the 2017 flag law (SR 232.21), "The Swiss flag shows a Swiss cross on a square background". Special provisions are made for the naval ensign and for civil aircraft identification.