The Silmarillion

Thus it came to pass in that time that the Númenóreans first made great settlements upon the west shores of the ancient lands; for their own land seemed to them shrunken, and they had no rest or content therein, and they desired now wealth and dominion in Middle-earth, since the West was denied. Great harbours and strong towers they made, and there many of them took up their abode; but they appeared now rather as lords and masters and gatherers of tribute than as helpers and teachers. And the great ships of the Númenóreans were borne east on the winds and returned ever laden, and the power and majesty of their kings were increased; and they drank and they feasted and they clad themselves in silver and gold.

In all this the Elf-friends had small part They alone came now ever to the north and the land of Gil-galad, keeping their friendship with the Elves and lending them aid against Sauron; and their haven was Pelargir above the mouths of Anduin the Great. But the King's Men sailed far away to the south; and the lordships and strongholds that they made have left many rumours in the legends of Men.

In this Age, as is elsewhere told, Sauron arose again in Middle-earth, and grew, and turned back to the evil in which he was nurtured by Morgoth, becoming mighty in his service. Already in the days of Tar-Minastir, the eleventh King of Númenor, he had fortified the land of Mordor and had built there the Tower of Barad-dûr, and thereafter he strove ever for the dominion of Middle-earth, to become a king over all kings and as a god unto Men. And Sauron hated the Númenóreans, because of the deeds of their fathers and their ancient alliance with the Elves and allegiance to the Valar; nor did he forget the aid that Tar-Minastir had rendered to Gil-galad of old, in that time when the One Ring was forged and there was war between Sauron and the Elves in Eriador. Now he learned that the kings of Númenor had increased in power and splendour, and he hated them the more; and he feared them, lest they should invade his lands and wrest from him the dominion of the East. But for a long time he did not dare to challenge the Lords of the Sea, and he withdrew from the coasts.

Yet Sauron was ever guileful, and it is said that among those whom he ensnared with the Nine Rings three were great lords of Númenórean race. And when the Úlairi arose that were the Ring-wraiths, his servants, and the strength of his terror and mastery over Men had grown exceedingly great, he began to assail the strong places of the Númenóreans upon the shores of the sea.

In those days the Shadow grew deeper upon Númenor; and the lives of the Kings of the House of Elros waned because of their rebellion, but they hardened their hearts the more against the Valar. And the nineteenth king took the sceptre of his fathers, and he ascended the throne in the name of Adûnakhôr, Lord of the West, forsaking the Elven-tongues and forbidding their use in his hearing. Yet hi the Scroll of Kings the name Herunúmen was inscribed in the High-elven speech, because of ancient custom, which the kings feared to break utterly, lest evil befall Now this title seemed to the Faithful over-proud, being the title of the Valar; and their hearts were sorely tried between their loyalty to the House of Elros and their reverence of the appointed Powers. But worse was yet to come. For Ar-Gimilzôr the twenty-second king was the greatest enemy of the Faithful. In his day the White Tree was untended and began to decline; and he forbade utterly the use of the Elven-tongues, and punished those that welcomed the ships of Eressëa, that still came secretly to the west-shores of the land.

Now the Elendili dwelt mostly in the western regions of Númenor; but Ar-Gimilzôr commanded all that he could discover to be of this party to remove from the west and dwell in the east of the land; and there they were watched. And the chief dwelling of the Faithful in the later days was thus nigh to the harbour of Rómenna; thence many set sail to Middle-earth, seeking the northern coasts where they might speak still with the Eldar in the kingdom of Gil-galad. This was known to the kings, but they hindered it not, so long as the Elendili departed from their land and did not return; for they desired to end all friendship between then: people and the Eldar of Eressëa, whom they named the Spies of the Valar, hoping to keep their deeds and their counsels hidden from the Lords of the West. But all that they did was known to Manwë, and the Valar were wroth with the Kings of Númenor, and gave them counsel and protection no more; and the ships of Eressëa came never again out of the sunset, and the havens of Andúnië were forlorn.