The sun had traveled past its noon mark when Lhachiel passed the first stones of the ruins. Her arrival had hailed some isolated warm greetings, yet predominantly raised eyebrows, the latter among those who had only heard, not ever crossed path with her. The sight of a woman bearing arms as readily as the men congregated within these ruins, was an unusual one, and Lhachiel was all too aware of this while trying not to show any signs of unease.
Whether the Last Bridge was built by the Arnorians or previous inhabitants of Eriador as far back as the First Age is unknown. The bridge fell under the domain of Arnor and then Rhudaur who maintained it. The Last Bridge marked the only crossing point over the Mitheithel (River Hoarwell) south of the Ettenmoors.
After Annúminas was abandoned, Fornost Erain became the capital of Arnor and then Arthedain after the split. The name itself means "Northern Fortress of the Kings." It was destroyed in 1974 of the Third Age during the war against Angmar, leaving the city a mass ruin. In the language of men it was known as Norbury with the nickname Deadman's Dike as it was believed to be haunted and avoided at all costs. Only the Rangers of the North were ever seen entering the city and none knew of what they did within.
From the start of its existence, Rhudaur was unfriendly towards the two other successor states, and took part in a bitter conflict with Cardolan over the tower of Amon Sûl and the Palantír associated with the tower.
The last Kings of Rhudaur were not of Númenórean blood, but were descended of Hill-men in service of Angmar. Under their rule the land became a vassal of Angmar, and thus enemies of Cardolan and Arthedain. - Tolkiengateway.net
"When the kingdom 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 is now remembered of them since Elrond departed...." (Lord of the Rings, Appendix A)
Calonimir stood before the hearth in the Hall of Fire, staring into the flames. Though a hot bath, a warm meal, and soft sheets had eased the aches of his body, his spirit was still in turmoil, and not even the clear voices of the Elves singing in the Hall could calm him. As he watched the fire dance upon the hearth, he thought yet again upon his meeting with Elrond and his sons and the charge that had been placed upon him.