Tharbad

[Valandil]

It would be better to do all my research first, and then post - but in this case I'm posting off the cuff, and asking others to chip in with tidbits, gleanings, opinions - whatever.

Tharbad had a long and unusual history. Located where the North-South Road crosses the River Gwathlo (Greyflood), it was continuously occupied for at least 4600 years. We know it had a great bridge over the river, and we surmise that it was the chief port of Arnor - for at least part of its life.

Let's see what happened with Tharbad over the years:
Second Age
c 1700 - Probably established by the Numenoreans as part of a line of forts up and down the Gwathlo. The chief Numenorean port on the Gwathlo appears to have been Lond Daer Ened - at the Gwathlo's mouth.
c 1700-2350 - Surmised to be the time when many of Numenor's Faithful migrated to Eriador (before building of Pelargir in 2350). Yet these settled mostly on the Lindon and Baranduin Rivers, rather than the Gwathlo.
3320 - Becomes a part of Arnor, when that kingdom is established by Elendil, following the Downfall of Numenor. Lond Daer Ened probably washed away by the upheavals, making Tharbad the chief, and perhaps only, seaport of Arnor.
3429 - Isildur, on his way to meet Elendil in the north, probably passes through Tharbad. Debarking here and continuing over land.
3441 - Elendil falls in combat with Sauron, and Isildur becomes King of Arnor.
Third Age
2 - Isildur slain with his older sons. Tharbad (as all Arnor) has no King.
10 - Valandil, youngest son of Isildur, becomes King of Arnor, and his heirs rule after him.
c 800 - Under Tarannon, as Captain of the Hosts, Gondor extends its control west to the Gwathlo (Note: Taronnon takes the crown of Gondor as Falastur - "Lord of Coasts" - so he must have gained them before becoming King). Is there a West Tharbad in Arnor, and an East Tharbad in Gondor? The Gwathlo had been Arnor's south-eastern border, and now becomes Gondor's western border as well.
861 - Division of Arnor, Tharbad becomes part of Cardolan.
1349 - Arthedain's new King takes the name "Argeleb" on coming to the throne - signifying Arthedain's claim over all of old Arnor. Rhudaur is said to resist this claim - so the implication is that Cardolan accepts it.
1409 - Angmar and Rhudaur attack Arnor, destroying Amon Sul, taking those at Tyrn Gorthad (Barrow Downs) and driving the Dunedain of Cardolan back to the edges of the Old Forest. This must sever Tharbad from the northern parts of the realm - although the invading army is defeated. Does Tharbad become more aligned with Gondor at this time?
1432-1447 - Gondor's War of the Kin-Strife.
1636 - The Great Plague enters Eriador from the southeast (Tharbad?) and most people of Cardolan perish, especially Minhiriath (the chunk of land due west of Tharbad - southwest from the Road, between Gwathlo and Baranduin. At this time - an end comes to the Dunedain of Cardolan, and evil spirits enter the deserted mounds at Tyrn Gorthad. Gondor is also devastated, and might remove whatever garrison it held at Tharbad. So - is Tharbad sundered from BOTH Dunedain Kingdoms? At least by land?
1974 - Arthedain destroyed by the Witch King of Angmar.
1981 - The Dwarves of Moria leave it to the Balrog and wander until they reach the north of Wilderland.
2510 - Gondor grants Rohan (formerly their Calenardhon) to the Eorlingas. Their sway seems to end at the Isen River - far short of Tharbad - indicating that Gondor was no longer connected.
2912 - Melting snows from the Fell Winter of 2911 flood Tharbad. The city is ruined and devastated. The bridge collapses.

Did I get anything wrong, or leave out anything important? What was Tharbad like? Maybe not very Dunedain-ish? Perhaps always sort of independent? Or cast about, as times changed?