Aman, the blessed kingdom, where the Valar live lazing around in Valinor, is the Tolkienan Olympus if we can say that. Seat of Valmar and Taniquetil, of treated and calm yards, of the great and severe hall, of the woods free from the vulgar presence of mortal beings. The time stream cannot be felt, and only ancient tales speak of them in the Land Beyond the Sea to Elves, Dwarves and Humans.
It is a kingdom where wars and clashes weren't seen for Ages and no one, not even Melkor and his armies, had the courage to confront.and to reach the Valinorian shore. In the Tale of Arda there is only one sovereign who, fatally in the end, moved against Aman. He is Ar-Pharazôn the Golden, 25th and last king of Númenor.
But before telling the results of the expedition that in 3319 SA sailed from the Numenorean harbor with black and gold sails, it is necessary to do an introduction, a preamble, about the life of the rash and brave king. Reading the Silmarillion we can early frame the subject. He had already grasped the scepter and sat on the throne in Armenelos, because he had usurped the throne, forcing queen Miriel to marry him, and he decided to be called Ar-Pharazôn. He was the most powerful and superb king that the Realm had ever had, and his government was centered on wars as nobody else's. No one among the kings of that age could compete with him.
When he heard about the raids of Sauron in Middle-earth and, worse, of Sauron's nickname, that is "King of Men", the monarch became furious. He resolutely arrived with his mighty fleets in Middle-earth. Occupying a hill, he set there the throne and the pavilions, invoking the arrival as soon as possible of Sauron, who was waiting to put hands in the affairs of Númenor. Sauron presented himself to the king as if in submission and, with enticements and smart movements, Sauron was able to obtain all he wanted. Thus Ar-Pharazôn, proud of his victory, went back to the Númenorean capital, dragging Sauron with him as a prisoner (3262 SA).
Early, with shrewdness, Sauron became next to the king, a happening which it's not possible to understand, but with which the paining pages of the story of Arda began. There cannot be justification for this fault, but there are some explanations: ambition, thirst for power, and the immeasurable pride of Ar-Pharazôn, added to what Sauron put in his mind and that was not a little.
As years passed away, the more the king lost his strength and judgment, as the more Sauron squeezed in his hands the regent and Númenor; it could be said that Sauron was ruling the Realm. In this way he put his puppet of Ar-Pharazôn against the Valar, telling him with affable voice that he was "the king of kings" and that he couldn't leave the Everlasting Lands to the Valar, and that owning those he would become immortal, and then he would be ten, one-hundred times more powerful and great than Manwë.
The king was convinced and, now a victim of insanity, sailed the sea on board Alcarondas, meaning "Sea Castle", bringing with him most of his army heading into a battle that he believed they could win easily. The target was clearly Aman, and the goal the Valar. While the strong army was settling in, Manwë summoned Ilúvatar who, without the need of an army, vanished Númenor under the impetuous waves and then dumped avalanches of soil on the king and his army that ended buried on the shores of Valinor.
Never in the songs could it be heard about a man so powerful as Ar-Pharazôn was; nevertheless, his ambition led him to the dark abyss of Ilúvatar's rage.