The Númenóreans were a scion of the Edain, the most noble race of Men in the First Age. This people was given the island of Númenor at the beginning of the Second Age by the Valar. The Dúnedain would be their immediate, noble descendants in Middle-earth.
As a reward for their services during the War of Wrath, the Valar gave to the surviving Edain an island continent in the western sea, which became Númenor, as their abiding place. They were also gifted with far longer life (300 years or more average), greater height, and greater wisdom.
Númenor, which had been raised up by Ulmo, was shaped like a star upon the ocean, and was in between Aman and Middle-earth. These Edain reached the island in the year SA 32. Elros, the brother of Elrond, was their first king
Most of Númenor was settled by Edain of the House of Hador, who were golden-haired and tall, with fair skin and blue eyes, while the North-western regions of the island were settled mostly by the people of the House of Bëor, who were generally dark-haired with grey or brown eyes.Few (if any) of the dwindling people of the House of Haleth had survived the ruin of Beleriand, though there is evidence that a small remnant passed over the sea to Númenor and brought with them the last Drúedain refugees that had dwelt at the Mouths of Sirion.However, these started leaving the island during the time of Tar-Aldarion, foreseeing the evil that would come. By the Downfall of Númenor the Drúedain had long left the island.
The Númenóreans were also on average very tall; with six foot, four inches being the average among them. Many far exceeded this height; Elendil himself bearing the nickname Elendil the Tall for being nearly eight feet high. One characteristic that set them apart from typical men was their longevity. Númenóreans were not immortal as the Elves or Ainur, however in gratitude for their service during the War of Wrath, they were blessed with extended lifespans averaging three times those of other men. Those descended from the House of Elros could live for around 400-500 years. They also aged more slowly than other Men and when they felt their period of vigour ending, were able to lie down and surrender their lives peacefully.
From the start, there was friendship between the Dúnedain of the West and the Eldar of Tol Eressëa. The white swan ships of the Eldar brought many gifts to the Númenóreans: birds, trees, herbs, and more. As time progressed, the Kings of Númenor began to envy the Eldar for their immortality, and a fear of death infected the island. Later on, kings fell dead, decrepit and witless, as they hopelessly clung to their lives. Thus faded the bliss of the Númenóreans, if not their power. They had sailed the earth to the East in their wooden ships, and even glimpsed from their tall ship prows the Gates of Morning, in the eastern continent. They founded many colonies in Middle-earth, north and south. With the gradual creation of a colonial empire, the pride of the Kings grew. The old customs were for the most part abandoned; those that were kept were kept out of fear of the Valar. Most of the Númenóreans, the King's Men, distanced themselves from the Eldar, and towards the end they persecuted any who were in fellowship with them. These were The Faithful, a small minority who still kept the old ways of reverence of the Valar and friendship with the Eldar.
The twenty-fifth and last king, Ar-Pharazôn, was made angry by the re-emerging Sauron in Mordor. The King sent a vast army, so large and imposing that Sauron found himself deserted by his own armies, without a single large battle fought. But what Sauron could not crush with his armies, he would manipulate with cunning mind and honeyed-tongue. He prostrated himself before Pharazôn, and was taken prisoner. In less than three years, the Dark Lord had gone from a prisoner to the King's greatest councillor. All save one (Lord Amandil of Andúnië) of the Council of the Sceptre came to almost worship Sauron as a god.
After many years, the king felt the shadow of death near, and Sauron, ever the opportunist, seized his chance. He told the aging king of "The Giver of Freedom and Life," Melkor, behind closed doors. The king, desperate to escape death, turned to the worship of the Dark. At Sauron's urging, a great temple was built, and the white tree Nimloth was cut down, though not before Isildur, Amandil's grandson, escaped with a fruit of the tree. In the year SA 3310, Sauron urged Pharazôn to take what the king desired for so long, the immortality of Aman. In nine years, a vast fleet was made ready, and Pharazôn, almost wavering, boarded his flagship, Alcarondas, and set sail. 39 days later, Númenor met with apocalypse. The king had landed on Aman, and the Valar ceded guardianship of Arda to Eru. Eru tore Aman away from the world, and formed the flat disc of Arda into a globe.
Númenor was flooded by a great wave, and its proud towers and walls crumbled. Míriel, the rightful queen of Númenor, attempted to ascend the peak of Meneltarma to escape the rising waters, but was overtaken and perished. Sauron, however, was taken unawares, and his physical form was destroyed, and "as a gale" he escaped. Not all the Númenóreans were killed, however. Nine ships, led by Elendil son of Amandil escaped to the northern regions of Middle-earth, and there founded the kingdoms of Gondor and Arnor. They were not the only Dúnedain to escape however, the race of Black Númenóreans survived in Umbar and Harad still, as well as the rest of the Númenórean colonies
Art Adam Burn the Guardians of Númenor