Wyvern folklore is rarely fire-breathing like the four-legged dragon. Sometimes modern fantasy book and media authors have wyverns that are frost-breathing or poison-breathing instead of fire-breathing. The current spelling "wyvern" is not attested before the seventeenth century as "winged two-footed dragon". According to the Oxford English Dictionary, it is an alteration of Middle English "wyver" (attested thirteenth century), from Anglo-French "wivre" (cf. French "guivre" and "vouivre"), which originate from Latin "vīpera", meaning "viper", "adder", or "asp". Conversely, medievalist William Sayers proposes a more complex origin for the term. He notes that the Anglo-French "guivre" and its Middle English derivative ceased to
Crosses in heraldry 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 the crucifixion of Jesus in use from at least the 2nd century. From the 11th century, and increasingly during the age of the Crusades, a variety of forms of cross symbols were developed for the purpose of the emerging system of heraldry, which appeared in western Europe in about 1200. The cross was displayed on banners and flags