This was a story told by the rosetta stone which ate the Shiryu-Shiryu no Mi. The story can be true, or just a fiction.
There are legends among the people of ancient kingdoms, Two story about the origins of human, devil fruits, the first sea-venturer, and the ancient kindom. There has been know two different version of the story existed. The first:
“Raf-el, (derived from ‘Araf and El) means Seeing the God, were the first land emerged to the surface. The God who created the Sun, created this holy land as a shrine of remembrance. The food delicious, the water isn’t salty, the temperature’s perfect, and the Sun, which is God’s Mercy, is beautiful. We, originated from the darkness of the sea, have given the honor to live in this soil of Heaven... Our mother, the Princess of the Sea has been rewarded, when she’s given and ate the Fruit of Eternity. She, like everyone else, was before imperfect, not suited to live in the heaven. The fruit then makes change, giving a pair of legs and forms for her and her descendants to live forever in the surface... But the delight of Raftel was not without envy. When the Sea people discovered that Our Mother has been chosen, they became blinded by wrath. Angered that the gift of the fruit was not given to everyone, they start calling the gift as the doing of Devil. Our mother and people who supported her were banished from the heaven. She’s drifting in the sea clinging on a log, as she cannot swim... Together with her people, and accompanied by the Sun -Mercy of God-, they ventured the sea in search for another soil of Heaven. The land was indeed found, the land of Merry and Joy, Mariejoa, and their descendants build our kingdom in there as a regard for them.”
The second story was a kind of opposite, though. Which:
“Our ancestors of the First Kingdom, were The Emperor and Empress of the Sea, so did we. Raf-el, (derived from A’raf and El) means The High Place of God, are the only known surface land which are considered as the holiest and the highest place –also the most beautiful place- in the First Kingdom. Our fish-man and mermaid ancestors made it as shrine of purity, where people pilgrimaged from their home far below the sea level to pray closer to The God... There were always peace, until The Devil, a reincarnation of darkness, tempted and fooled Our Mother, the innocent Mermaid Princess to ate the Devil Fruit in Raftel. The fruit changed the appearance of our mother, giving her form like us, disabling her ability to swim, making her a permanent resident of surface. Opinions divided, some believe that the fruit is a gift and a sign from God that all future fish-man should life in the surface, while others considered eating the fruit which belong to God would bring the anger of God, and Our Mother should be banished. The difference were so extreme that it divides the country and leads to civil war. Years of war devastated our original home, the winning side banished the other. The Princess, blamed for being the cause of war, are too banished... She is clinging on a log for days, no, for months until they found a land. The land of Merry and Joy, Mariejoa. But the joy was not for long, her two-legged descendants who are tainted by the devil declared war to the fish-man descendants and their supporters, believing that the surface belongs only to the gifted, human. Even though they are outnumbered, they are winning by exploiting the power of the now forbidden Devil Fruits. The fish-man and mermaids are forced to retreat to the deep, never again allowed to see the surface. Human who supported the fish-man, however, survived the slaughter and decided to go to Raftel to stop the badbringing of the Devil Fruits. To fights the Devil... Long story short, these people won Raftel, restored it as a Heaven, where people and fish-man alike can live in peace and prosper. That is where our kingdom formed as a regard to their dreams and dedications.”