Sauron taken as prisoner to Númenor
Event Type: Political
Age: Akallabêth/Last Alliance
"Then he sent forth heralds, and he commanded Sauron to come before him and swear to him fealty.
And Sauron came. Even from his mighty tower of Barad-dûr he came, and made no offer of battle. For he perceived that the power and majesty of the Kings of the Sea surpassed all rumour of them, so that he could not trust even the greatest of his servants to withstand them; and he saw not his time yet to work his will with the Dúnedain. And he was crafty, well skilled to gain what he would by subtlety when force might not avail. Therefore he humbled himself before Ar-Pharazôn and smoothed his tongue; and men wondered, for all that he said seemed fair and wise.
But Ar-Pharazôn was not yet deceived, and it came into his mind that, for the better keeping of Sauron and of his oaths of fealty, he should be brought to Númenor, there to dwell as a hostage for himself and all his servants in Middle-earth. To this Sauron assented as one constrained, yet in his secret thought he received it gladly, for it chimed indeed with his desire. And Sauron passed over the sea and looked upon the land of Númenor, and on the city of Armenelos in the days of its glory, and he was astounded; but his heart within was filled the more with envy and hate."
The Silmarillion, Akallabêth