Eärendur, son till Elendur, var Arnors sista kung per se , döende i 861 i tredje ålder enligt bilaga B till Ringenes Herre . Bilagan noterar vidare:
After Eärendur, owing to dissensions among his sons their realm was divided into three: Arthedain, Rhudaur, and Cardolan. Arthedain was in the North-west and included the land between Brandywine and Lune, and also the land north of the Great Road as far as the Weather Hills. Rhudaur was in the North-east and lay between the Ettenmoors, the Weather Hills, and the Misty Mountains, but included also the Angle between the Hoarwell and the Loudwater. Cardolan was in the South, its bounds being the Brandywine, the Greyflood, and the Great Road.
Således var Arnor i 1975 faktiskt i tre delar. De tre erövrades eller avvecklades vid olika tidpunkter; Bilagan berättar för oss:
A great host came out of Angmar in 1409, and crossing the river entered Cardolan and surrounded Weathertop. The Dúnedain were defeated and Arveleg was slain. The Tower of Amon Sûl was burned and razed; but the palantír was saved and carried back in retreat to Fornost, Rhudaur was occupied by evil Men subject to Angmar, and the Dúnedain that remained there were slain or fled west. Cardolan was ravaged. Araphor son of Arveleg was not yet full-grown, but he was valiant, and with aid from Círdan he repelled the enemy from Fornost and the North Downs. A remnant of the faithful among the Dúnedain of Cardolan also held out in Tyrn Gorthad (the Barrowdowns), or took refuge in the Forest behind.
Således, genom 1409 Rhudaur (en stor bit av Arnor) existerade inte längre som sådan. Cardolan var tilltering och fanns knappt. Nästa:
In the days of Argeleb II [the mid-1600s Third Age] the plague came into Eriador from the Southeast, and most of the people of Cardolan perished, especially in Minhiriath. The Hobbits and all other peoples suffered greatly, but the plague lessened as it passed northwards, and the northern parts of Arthedain were little affected. It was at this time that an end came of the Dúnedain of Cardolan, and evil spirits out of Angmar and Rhudaur entered into the deserted mounds and dwelt there.
Så vid år 1660 fanns inte Cardolan effektivt som ett land längre och var i huvudsak öde.
Kampen 1975, som hölls för att vara slutet av nordriket, var alltså bara slutet på Arthedain; De andra två tredjedelarna av Arnor hade mer eller mindre helt avvecklats århundraden tidigare.
Arthedain själv var naturligtvis där Shire och Bree-landet var; och vi fick tips om att det fanns andra hobbits och kanske andra människor i området - men så långt som resten av Arnor verkar det ha varit ingen annan där; absolut ingen bosättningar. Orker blev ett problem, som började ett par hundra år före Bilbos resa. men bara sällan utanför de östligaste områdena:
When the kingdom [that is, Arthedain] ended the Dúnedain passed into the shadows and became a secret and wandering people, and their deeds and labours were seldom sung or recorded. Little now is remembered of them since Elrond departed. Although even before the Watchful Peace ended evil things again began to attack Eriador or to invade it secretly, the Chieftains for the most part lived out their long lives. ... later, in the days of Arassuil, Orcs, multiplying again in the Misty Mountains, begin to ravage the lands, and the Dúnedain and the sons of Elrond fought with them. It was at this time that a large band came so far west as to enter the Shire, and were driven off by Bandobras Took.
(Alla citat som tas från Bilaga B till Ringenes Herre .)