They did not meet the Witch-king at Fornost, but on the plains east of it toward Lake Evendim, home of the ancient kings of Arnor, Annúminas.
In 2043, King Eärnil II of Gondor passed away and his son, the Witch-king's old enemy, Eärnur inherited the throne.
He entered the city's gates and was never seen again, thus ending the reign of the Gondorian Kings and causing the beginning of the ruling Stewards of Gondor.