In the book of Genesis in the Bible, Noah was the hero chosen by God to survive a great flood on earth. The biblical story was probably based on similar accounts of a flood in myths from Mesopotamia*.
According to the story in Genesis, the human race had become so wicked that God was sorry he ever created it. He decided to wash away all the creatures of the earth in a great flood. However, God saw that Noah was a righteous man so he decided to save him. God told Noah of his plans and instructed him to build a great ark in which he could ride out the storm with his wife and children. Then he commanded Noah to find male and female specimens of every type of animal on the earth and bring them into the ark and also to gather plants and seeds. Noah followed God's instructions and entered the ark as the rain began to fall.
It rained for 40 days and 40 nights, until the waters covered even the tops of the highest mountains. After the rain ended, Noah released a raven and a dove to find out whether there was any dry land on earth. Both birds returned, indicating that water still covered the planet. Seven days later, Noah sent the dove out again. This time it returned with an olive branch, which meant that dry land had finally appeared. According to later Jewish legend, the ark came to rest on the top of Mount Ararat (in what is now Turkey), and Noah and his family emerged with all the animals.
Noah built an altar and made a sacrifice to God. God then made a covenant, or agreement, with Noah, promising never again to devastate the earth because of the wickedness of humans. He placed a rainbow in the sky as a reminder of this covenant.