The
Black Númenóreans of Third Age
Middle-earth were the descendents of the
Kings Men of the
Second Age.
Tolkien suggests that most of the
Númenórean settlements in Middle-earth were south of
Umbar. What later became
Gondor and
Arnor were settlements of
the Faithful Númenóreans of the second half of the Second Age, and these were the minority party of Númenórean society.
From
Return of the King, “Gondor and the Heirs of Anárion”, in the footnotes:
The great cape and land-locked firth of Umbar had been Númenórean land since days of old; but it was a stronghold of the King's Men, who were afterwards called the Black Númenóreans, corrupted by
Sauron, and who hated above all the followers of
Elendil. After the fall of Sauron their
race swiftly dwindled or became merged with the Men of Middle-earth, but they inherited without lessening their hatred of Gondor. Umbar, therefore, was only taken at great cost.
Umbar was first settled by Dúnedain in the Second Age, perhaps around 1800; it was “made into a great
fortress of
Númenor” in 2280, and Pelargir, which became the chief haven of the Faithful, was founded in 2350.
With the Downfall of Númenor, the
Akallabêth, much of the western shore of Middle-earth was hit with a tsunami. Besides that, many of the Kings Men of Middle-earth joined with
Ar-Pharazôn’s invasion force against
Valinor. So the populations of Umbar and many other Númenórean settlements along the coasts were probably depleted. Moreover, the Dúnedain settled in these
regions were already in rebellion against
Eru and the
Valar: in all likelihood, their society quickly decayed, and they intermingled with other Men. The marriage of Tarannon Falastur, the tenth
king of Gondor, to Queen Berúthiel was likely a dynastic marriage to heal the rifts between the Faithful
Elendili of Gondor and the now-called Black Númenóreans, formerly the Kings Men, south of Umbar (and inland). Falastur died in Third Age 913, so we may safely assume that, although the unhappy marriage was unconsummated (Berúthiel was apparently beautiful but really weird), there was a ruling dynasty somewhere in
Far Harad sufficiently widely recognized to make such a (risky) union worthwhile: they were probably at least related to
the old ruling house of Númenor, if not a cadet (junior) branch of the old royal house.
About 400 years later, Castamir the Usurper overthrew Eldacar son of Valacar on the pretense that Eldacar was not pure-blooded Dúnedain. Although Eldacar defeated and killed Castamir at the Crossings of Erui west and south of
Minas Tirith, Castamir’s sons and followers escaped downriver to Pelargir and thence commenced to Umbar, which had become a stronghold of Gondor’s after Falastur’s nephew Eärnil invested it. Umbar was never again under the control of Gondor until the days of
King Elessar.
The Kings Men had turned away from their traditional theology their forefathers learned from the Eldar (which fit with their own traditions they brought with them into
Beleriand) and embraced religious beliefs more to their liking. Some of them might have secretly (or not so secretly) worshipped Sauron in the Second Age even before he was imperiously (and foolishly!) taken to Númenor by the impious Ar-Pharazôn. Three of the
Nazgûl were recruited from the Númenóreans, and it is likely that for many years, they also travelled amongst their kinsfolk, perverting their minds and beliefs. Sauron’s return from the destruction of Númenor must have seemed to them a miracle, confirming their belief that he was, as he styled himself, a god-king. The Black Númenóreans returned to their worship of Sauron: from his description of Berúthiel published in an interview with Tolkien in the 1960s, it certainly sounds as if she was also a worshipper of Sauron; she was at least a practitioner of his teachings.
As for Ar-Pharazôn, he was not “betrayed” by Sauron so much as he was
cozened by Sauron. Sauron told him what he wanted to hear, then encouraged him to act upon it. Pharazôn tried to invade Valinor because he wanted to invade Valinor. It was what the Kings Men wanted to hear, too. The surviving Black Númenóreans probably fought against Elendil and
Gil-galad for Sauron in the
War of the Last Alliance: they were just a continuation of what already existed.
Late in
the Third Age, the Corsairs were a continuation of the Númenórean sea-faring tradition, a tradition that included (as it had with real-world Vikings) sudden appearances of
ships along the coasts for raiding and kidnapping. The defection of Castamir’s family and followers midway through the Third Age strengthened the folk of Umbar while simultaneously weakening Gondor, leaving it vulnerable to these raids. By the way,
Aragorn’s surprise appearance in and assault from the black-sailed ships is emblematic not of Corsair raids, but of Númenórean military strategy in the Second Age, of which Corsair raids were also an echo. (Cf. Viking invasions.)
In the
War of the Ring, Aragorn seized the naval expedition of Umbar at Pelargir using the
Dead Men of Dunharrow. Nearly all the
Haradrim (Corsairs) were killed or captured. (And frankly, it doesn’t sound like the Dúnedain of Gondor were too interested in capturing Corsairs.) At the end of the war, King Elessar “made peace with the
peoples of
Harad”: it’s probably safe to assume they recognized his
suzerainty, so that sooner or later, Umbar and Harad - and the Black Númenóreans - once again fell under the dominion of Gondor.