A flood myth or deluge myth is a story about a great flood caused by one or more gods. This flood usually destroys civilization as a form of punishment. People often compare the floodwaters in these myths to the ancient ocean described in some creation stories. In these myths, the flood is sometimes seen as a way to cleanse society or remove human corruption, preparing the way for a new beginning. Most flood myths also include a hero who represents the human desire for life.

The oldest known story about a flood sent by gods comes from Sumerian culture in Mesopotamia. This story is also found in the Akkadian Atra-Hasis epic, which dates to around 1800 BCE. Similar flood stories appear in many other cultures, such as the biblical Genesis flood story, the manvantara-sandhya in Hinduism, the Greek myth of Deucalion, and in the traditions of indigenous North American peoples.

Mythologies

The Epic of Gilgamesh (around 2100–1800 BCE) describes a great flood that destroys all humans except one family. This story is believed to have been influenced by an earlier tale called the Atra-Hasis epic. In the story, a group of Sumerian gods from different groups decides to change the Earth’s dry steppe, called "Eden," into a fertile garden. This change introduces farming, a key part of the Neolithic Revolution. The hard work required to farm causes a rebellion among the lower gods. To stop the conflict, the gods create humans in pairs to do the work and reproduce. Over time, humans multiply so much that they disturb the upper gods with their noise. Enlil, the most powerful god, decides to send a flood to destroy humanity. Enki, a rebellious god, secretly warns his priest, Atrahasis, about the flood. He gives Atrahasis instructions to build a boat, and the Atrahasis family survives, saving humanity.

A similar story, the Eridu Genesis (around 1600 BCE), was found on clay tablets discovered in Nippur in the late 1890s. It was translated by a scholar named Arno Poebel.

Scholar Yi Samuel Chen studied texts from the Early Dynastic III Period to the Old Babylonian Period. He found that the flood story was added later, during the Old Babylonian Period. In the Sumerian King List, the section before the flood is written differently from the rest of the list. Old Babylonian copies show a tradition about events before the flood, separate from the main King List. However, copies from the Ur III Period and the Brockmon collection suggest that the King List originally existed without the flood story. Chen argues that the flood story and the section before the flood were added later during the Old Babylonian Period. He also notes that the flood became a significant event in early history, as it first appears in Old Babylonian texts and not in earlier Ur III copies. Chen explains that the name Ziusudra, a flood hero, and references to the flood in the Old Babylonian version of "Instructions of Shuruppak" were added during this time, along with updates to the text.

In the Hebrew Bible, the story of the flood appears in the 9th century BCE or 5th century BCE. The god Yahweh, who created humans from the dust of the Earth, decides to flood the world because people have become corrupt. Yahweh tells Noah to build an ark to save humans and animals. Noah, his family, and representatives of all animals enter the ark. When the flood begins, everything outside the ark dies. After the flood ends, Noah and his family leave the ark, and Yahweh promises never to flood the Earth again. He makes a rainbow the sign of this promise.

In Hinduism, texts like the Satapatha Brahmana (around 600 BCE) and the Puranas describe a flood. In this story, the god Vishnu appears as Matsya, a fish, and warns the first man, Manu, about the flood. Matsya advises Manu to build a large boat. In Zoroastrianism, a drought caused by the evil spirit Ahriman is ended by the god Mithra, who shoots an arrow into a rock, causing a flood. One man survives in an ark with his cattle. A scholar named Norbert Oettinger believes the story of Yima and the Vara was originally a flood myth. He argues that the harsh winter added to the story later was due to the dry climate of Eastern Iran, where floods were less common. Oettinger also notes that a reference to melted water in the Videvdad 2.24 may be a remnant of the flood myth. He explains that early Indian flood myths had Yama as the hero, but this was later changed to Manu.

In Plato’s Timaeus (written around 360 BCE), the flood story describes a race of humans called the Bronze race who anger the god Zeus with their constant fighting. Zeus decides to punish them with a flood. Prometheus, who created humans from clay, tells his son Deucalion about the plan. Deucalion builds an ark to survive. After nine days and nights of flooding, the water recedes, and the ark lands on a mountain.

The Cheyenne, a Native American tribe from the Great Plains, have a tradition that a flood changed their history, possibly in the Missouri River Valley. The Blackfeet, another Great Plains tribe, tell a story called "Language on a Mountain." In this story, the god Napi, also called Old Man, recounts a great flood. After the flood, Napi made the water different colors. He gathered people on a mountain and gave them water of different colors to drink. When they spoke, everyone except those who drank black water spoke different languages. Those who drank black water spoke the same language and became the Blackfoot, Piegan, Siksika, and Blood tribes. This story is said to have happened on the highest mountain in the Montana reservation.

The Hopi, a Native American tribe in the southwestern United States, have a tradition of a flood that nearly reached the tops of the mountains. Other Puebloan tribes share similar flood stories.

Historicity

Mesopotamia, like other early river valley civilizations, was often flooded. Large floods could destroy entire communities. Excavations at Shuruppak (modern Tell Fara, Iraq) from the 1930s showed a thick layer of yellow sand and clay between the Jemdet Nasr and Early Dynastic layers. This layer suggests a flood caused by a sudden river change, a common event in the Tigris–Euphrates river system. Similar layers have been found at other sites, each dating to different times, which matches the pattern of river changes. In Mesopotamian legends, Shuruppak was the city of Uta-napishtim, a king who built a boat to survive a flood. The alluvial layer at Shuruppak dates to about 2900 BCE.

The geography of Mesopotamia changed greatly as the Persian Gulf filled with water after sea levels rose following the last ice age. Around 18,000 years ago, global sea levels were about 120 meters (390 feet) lower than today. Sea levels rose until about 8,000 years ago, reaching current levels. The Persian Gulf was once a large, low-lying, and fertile region. Human settlements near the Gulf Oasis are thought to have existed for about 100,000 years. A sudden increase in settlements above today’s water level occurred around 7,500 years ago.

Historian Adrienne Mayor suggested that global flood stories might have come from ancient people finding seashells and fish fossils in inland and mountain areas. Ancient Greeks, Egyptians, and Romans recorded such discoveries. The Greeks believed Earth had been covered by water multiple times, using seashells on mountain tops as evidence.

Some theories link the Deucalion myth to a large tsunami in the Mediterranean Sea caused by the Thera eruption (around 1630–1600 BCE). The tsunami affected the South Aegean Sea and Crete but did not reach mainland Greek cities like Mycenae, Athens, or Thebes, which continued to grow. This suggests the event had a local, not widespread, impact.

The Black Sea deluge hypothesis suggests a major flood occurred around 5600 BCE when water from the Mediterranean Sea rushed into the Black Sea. This idea has sparked much debate. Another theory, the Younger Dryas impact hypothesis, proposed that a comet caused flood myths, but this was later rejected.

The earliest known idea about a comet affecting humans was proposed by Edmond Halley in 1694. He suggested a near-miss by a comet caused a worldwide flood. William Whiston, a follower of Isaac Newton, later wrote in his book A New Theory of the Earth (1696) that a comet caused the Biblical Flood of Noah in 2342 BCE. He also linked comet impacts to changes in Earth’s atmosphere.

In 1796, Pierre-Simon Laplace wrote about similar ideas in his book Exposition Du Systême Du Monde.

In 1883, Minnesota congressman Ignatius L. Donnelly wrote Ragnarok: The Age of Fire and Gravel, suggesting a comet struck Earth around 6,000–9,000 BCE, destroying an advanced civilization on the "lost continent" of Atlantis. He linked this event to the Biblical Flood and to climate changes.

Archaeologist Bruce Masse studied 175 flood myths from around the world. He proposed that some myths might describe a tsunami caused by an oceanic asteroid impact near Africa and Antarctica around 2807 BCE. This event, he suggested, could have created the Burckle Crater and Fenambosy Chevron underwater and led to a massive tsunami. Some myths mention a solar eclipse, planetary alignments, or the end of the reign of the Chinese goddess Nüwa.

Floods after the Last Glacial Period (about 115,000–11,700 years ago) are thought to have inspired flood myths still told today. Plato’s story of Atlantis, set 9,000 years before his time, may describe a Stone Age society near the Mediterranean Sea destroyed by rising sea levels.

Art

• The Matsya incarnation of Lord Vishnu helps Manu's boat after defeating a demon.
• An illustration of Nanabozho in an Ojibwe flood story from R.C. Armour's book North American Indian Fairy Tales, Folklore and Legends (1905).
• The Great Flood, painted by an unknown artist, is part of the vom Rath bequest at the Rijksmuseum.
• The Deluge, created by Francis Danby in 1840. Oil on canvas. Tate Gallery.
• Noah's Ark from the Zubdat al-Tawarikh manuscript, displayed in the Museum of Turkish and Islamic Arts in Istanbul. Dedicated to Sultan Murad III in 1583.
• Study for The Deluge, a 1843 painting by William Etty, shows the aftermath of a mythological deluge, also known as a "great flood."