We don't have an exact date for the point when these people first started referring to themselves as the 'King's Men'. It was during the reign of Tar-Atanamir that a faction of the Númenóreans first began to turn against the Eldar and the Valar, and this was clearly the beginning of the movement. The name 'King's Men', however, is not formally recorded until the time of Tar-Atanamir's successor, Tar-Ancalimon, who ruled from II 2251 to II 2386. All we can say for sure is that the King's Men emerged at some point during the reigns of these two Kings, and that they definitely existed at the time of Tar-Ancalimon's death in II 2386.
Just as for their beginning, we have no specific date on which the King's Men ceased their activities. The last we specifically hear about them is during the reign of Tar-Palantir (II 3177 - II 3255), to whom they were implacably opposed. After Tar-Palantir's death, the throne of Númenor was usurped by Ar-Pharazôn, who entirely shared the convictions of the King's Men. At this point, with the Ruler of Númenor acting exactly as they would wish, there was little purpose in the King's Men continuing their activities, so it is unsurprising that we have no mention of them during Ar-Pharazôn's rule. It is certain that there were no more King's Men after II 3319, the year in which Ar-Pharazôn took the philosophy of the King's Men to its extreme conclusion and attempted to invade Aman, bringing about the Downfall of Númenor. |