: Since the sailors and soldiers of the garrison had to eat they
: probably also had some sort of agricultural system (either of
: their own or forcing the 'natives' to work for them). When you
: say "these people" do you mean the Numenoreans or the "wild
: folk"? If I am not mistaken, Lond Daer would have been included
: in the borders of Cardolan, so the Numenoreans became a part of
: the Kingdom of Arnor and subsequently of the Kingdom
: (Principality?)of Cardolan. Since we do know that the Dunedain
: of Cardolan at some point in time died out, we must assume that
: the descendants of the Numenoreans no longer existed at the
: time of the WoR or perhaps had degenrated to a more 'humble'
: status. As for the wild people, they were the ancestors of the
: Dunlandings, weren't they?

Lond Daer Ened ("The Great Middle Haven", referring to Pelargir and Mithlond) originated as Aldarion's seasonal haven Vinyalonde. He did not settle there permanently and the haven could not have been colonized prior to SA 1200, which is when the Numenoreans began making permanent havens in Middle-earth.

Since the name it eventually took implied it was one of three great havens in the north, Mithlond and Pelargir being the other two, we must infer that name was not bestowed until sometime after SA 2350. Vinyalonde was usable, and perhaps inhabited, in SA 1700, when the Numenorean admiral Ciryatur sent part of his fleet to the haven to land a force behind Sauron's lines (Sauron was at that time controlling all of Eriador from the Lhun to Rivendell).

We don't know when Lond Daer Ened was eventually abandoned, but I infer this happened sometime in the Second Age, perhaps after the Downfall of Numenor, when the coasts of Middle-earth were ravaged. Pelargir, which had been a seaport up until then, found itself isolated inland along the shore of the Anduin. In Unfinished Tales there is a note where Tolkien writes that in the early days travel between Gondor and Arnor was fastest by ship travelling from Anduin to Tharbad. This seems to imply that Lond Daer Ened was no longer inhabited.

The Numenoreans began forifying the Gwathlo sometime after Aldarion's day in reaction to the raids from the Gwathuirim (who were alarmed by the Numenoreans' lumbering in the region). The Gwathuirim were the "wild folk" living on both sides of the river. These were related to the wild men of the White Mountains (from whom came the Dead Men of Dunharrow) and the Folk of Haleth, the Second House of the Edain. A series of forts was built along the river and Sauron bypassed these forts when he invaded Eriador, but their garrisons were apparently too small to form an effective force against him.

Sometime before Elrond retreated to Rivendell, the Numenoreans made a port at Tharbad (in fact, this was probably well before the War of the Elves and Sauron). We can infer this because they did not at that time know the sources of the Gwathlo were two rivers, the Mitheithel and Bruinen.

The Gwathuirim helped Sauron during the war and they burned many timber stockpiles belonging to the Numenoreans. Sauron's scorched Earth policy, however, destroyed the great forest lands and the surviving Gwathuirim fled into the woods on the cape of Eryn Vorn (a piece of land jutting out just below the mouth of Baranduin) and the hills of eastern Enedwaith. It is reasonable to suggest (though by no means is it certain) that the Men of Bree were descended from the refugees who fled to Eryn Vorn. The Dunlendings were descended from the refugees who fled to the hills of eastern Enedwaith.

Tharbad survived until Third Age 2912, when it was destroyed by floods resulting from the Fell Winter of 2911. By then it was just a small town, but when Gondor and Arnor were stronger the two kingdoms had maintained forts there, one on either side of the river, and there had been great causeways leading up to the forts.

Gondor withdrew its garrison after the Great Plague of 1636 (or else the garrison died out and was not replaced). Tolkien doesn't say what became of Tharbad when Arnor was divided into three smaller kingdoms but it seems reasonable to infer that Cardolan took control of it (and therefore probably of the garrison).

But Cardolan's kings died out by 1350 and the princes of Cardolan appear to have accepted Arthedain's kings as rulers, perhaps maintaining themselves semi-independently, as the Lords of Dol Amroth did after the end of the Kings of Gondor. In 1409 the last prince of Cardolan perished in battle with the forces of Angmar so Cardolan became re-integrated into the kingdom of Arnor. Then, except for Tharbad and few wanderers in the (rejuvenated) woodlands of Minhiriath, most of Cardolan's people died in the Great Plague.

One attempt was made to recolonize Cardolan (sometime in the 1800s), but by then the barrow-wights had settled in Tyrn Gorthad and the colonists were too terrified to remain nearby, so the attempt failed.
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