The Witnesses of Manwë were associated with the Hallow of Eru on the Meneltarma from the earliest times of Númenor, and especially with the tradition of the Three Prayers. The Eagles kept watch over the Meneltarma through the centuries that followed, but we're not told how they reacted during the reigns of the later Kings, who turned away from the traditions of earlier times. It may be relevant that the Eagles that nested on the royal palace in Armenelos departed from their eyrie during the rule of Tar-Ancalimon (II 2251 - II 2386), but it is not said that these Eagles were directly connected with the Witnesses of Manwë.

The Three Prayers were abandoned by King Ar-Gimilzôr on his accession in II 3102, and it may be that the Witnesses abandoned their watch over the Meneltarma at this time. Ar-Gimilzôr's successor Tar-Palantir reinstated the Three Prayers, however, so we might expect that the Witnesses of Manwë would have returned, at least during Tar-Palantir's reign. At the very latest, the Witnesses must have left Númenor by II 3319, because that was the year of the Downfall, in which the island was lost beneath the waves of the Great Sea.