[Mandos]

I have always loved the kind of mystery of the realm of Agmar, and would like to discuss it. First, when was this realm founded, and by who? I of course know about the witch king, but who was he, a dark Numenearon? And when was this kingdom destroyed, and how was it destroyed? Finally, why was Agmar founded? I realize that it was majorly due to Agmar the Arnor was lost, but why did Agmar kind of disapear? I would like to hear your thoughts about these questions.