Arvedui was a dunadan and the fifteenth, and last King of Arthedain. When he was born, Malbeth the Seer foretold he would be the last, so his father, Araphant, gave him the name Arvedui, meaning 'king-last'.
In 1944 when Ondoher, King of Gondor, and both his sons died, Arvedui made a claim for the kingship of the Reunited Kingdom. This claim was rejected and the kingship was given to Earnil.
When attacks from Angmar started to happen in Arnor, Earnil promised aid to Arvedui. Before the fleet arrived though, the Witch-king took Fornost. Arvedui held the northdowns but soon, he was forced to flee north and Arthedain was overrun.
Arvedui's sons had been sent to Cirdan in Lindon, and when Cirdan was told that Arvedui was in the north, he sent ships to find him.
Meanwhile, Arvedui and his guard soon found the Snowmen of Forochel who gave him food and aid. They were reluctant though, for they were afraid of the Witch-king. Eventually, they were persuaded by the King and his men's weapons.
When the ship arrived, the snowmen were scared and amazed. "Do not mount this sea monster!" they said, "You may stay here till the Witch-king goes home. For in summer his power wanes; but now his breath is deadly, and his cold arm is long."
Unfortunately, Arvedui did not heed this counsel and left after he gave the chief of Lossoth the ancient ring of Barahir.
On the way back to Lindon, the ship hit ice and it sank, drowning Arvedui, and with him went the palantir of Annuminas and Amon Sul.
Arvedui's sons, Aranarth and Arahael started the line of the Chieftains of the Dunedain. Aranarth became the first Chieftain and Arahael became the second.