From ancient Greek myths to Game of Thrones, the legend of the dragon is one of the most enduring and romanticized throughout history. It has been traced back as far as 4000 BC and exists in all parts of the world. In and around Europe dragons are viewed mostly as monsters of evil intent. In ancient Rome, the army used dragons as symbols of strength.During the Renaissance, fear of sea monsters kept sailors from venturing too far from known waters, and the edges of their maps would read “Here be dragons.”Considered one of the great medieval world maps. Probably a copy of the map that adorned the bed chamber of King Henry III.The Oxford English Dictionary explains the etymology of the word dragon, which it says entered the English lexicon in around 1220 and was used in English versions of the Bible from the early 14th century.Dragon derives from Old French, the language used by nobles and law courts following the Norman conquest of 1066. This in turn stems from the Latin draconem or draco meaning “big serpent,” which was derived from ancient Greek δράκων (drakon).An early appearance of the Old English word dracan in Beowulf; a heroic poem of the 8th century,In Greek mythology, the Hesperian Dragon named Ladon was a hundred-headed serpent that guarded the golden apples in the garden of the Hesperides.Historically, European dragons were viewed as being evil, jealous, and greedy hoarders of treasure.Ancient Greek mosaic from Caulonia, Italy, depicting a cetus or sea-dragon.In the stories, they were generally treated as violent monsters who must be slain by heroes and saints. European dragons could have four legs, two legs, or none, and often had wings.Illustration of a winged, fire-breathing dragon by Friedrich Justin Bertuch from 1806.In Asia, and especially China, the view of these creatures was very different. Dragons were thought to live under the ocean in the winter, arising in the spring with a clap of thunder to bring the rain needed for their crops, according to the American Museum of Natural History.Carved imperial Chinese dragons at Nine-Dragon Wall, Beihai Park, Beijing. Photo by splitbrain CC BY-SA 2.0They breathed clouds and moved the seasons. The dragon was the symbol of the Chinese Emperor, and the Imperial throne was called the Dragon Throne. Known as the Dragon, the emperor ruled in harmony, and brought peace and prosperity to all.In Chinese history, the Dragon Throne of the Emperor of China (pictured here in the Palace of Heavenly Purity) was erected at the center of the Forbidden City, which was itself regarded as the center of the world.Chinese dragons are depicted as being more serpent-like, with long, snaking bodies and usually had four legs. They are generally seen as wingless.How people view them and what they believe about them varies widely, but the idea is too widespread not to think there are some common roots.Painting of a Japanese dragon by Hokusai (c. 1730 – 1849).What made people from cultures that may have never met all come up with the idea of dragons?There are several theories about what creatures could have been the source of the dragon myths, any or all of them may be true.Attic red-figure kylix painting from c. 480–470 BC showing Athena observing as the Colchian dragon disgorges the hero Jason.Ancient Origins discusses a number of potential roots. The first one is crocodiles. Saltwater and Nile crocodiles are the two largest living reptiles on earth today.Currently, saltwater crocodiles live in the eastern Indian Ocean region, and Nile crocs in the rivers, marshes, and lakes of Sub-Saharan Africa. But 1,000 years they had a much larger habitat range, and could have been encountered by people living in Greece, Spain, and Southern Italy.Bizarre Blue Dragon-Like Creatures Wash Up on Beach, Experts Warn Not to TouchNile crocodiles can grow to 20 feet in length, and have the ability to lift much of their bodies off the ground. This may be a hint about why European dragons are often described as rearing up.Young Nile Crocodile gaping while basking in the sun.Many archaeologists believe that ancient people envisioned dragons when they found the fossils of certain sorts of dinosaurs, specifically, the types that had very long necks.Having no explanation for the lengthy fossils, they would have imagined a beast that seemed to fit what they were seeing.A bone of the legendary Wawel Dragon (Smok Wawelski), outside Wawel Cathedral, Krakow, Poland. Photo by Yohan eunan CC BY SA 3.0There is evidence to suggest that there were discoveries of dinosaur fossils being uncovered in China as early as the 4th century BC. Fossils belonging to flying dinosaurs, such as pterodactyl or pteranodons, could very well be part of why some cultures envision dragons as having wings.Another, similar, theory is that people imagined dragons when the skeletons of whales washed on shore near early coastal dwellings.Because early people didn’t have suitable sailing and navigation technology, they would most likely only have seen the immense whales from a distance when the creatures were living.The Destruction of Leviathan (1865) by Gustave Doré.This could certainly be the root of sailor’s fear of “dragons” in the waters, as well as the ocean-dwelling Asian view. This could also be one of the reasons that some dragons are pictured as having wings.A medieval bestiary dated to around 1260 AD, contains the oldest recognizable image of a fully modern, western dragon.Snakes are also thought to be a basis for the dragon myth. Although even very large snakes are much smaller than dragons are said to be, humankind has a deeply embedded instinct to fear them.Illustration from an ancient Egyptian papyrus manuscript showing the god Set spearing the serpent Apep as he attacks the sun boat of Ra.In ancient Egypt, for example, Apep was a deity known as the Serpent of the Nile. He was viewed as the lord of Chaos, and opposed to light and truth.Read another story from us: The bizarre story of the dragon’s rib in the cathedral of AtessaEach of these theories show some echo of what we think about when we think of dragons. All of them together show a more complete picture of the huge beasts that feature in so many stories and myths.