Neuschwanstein-related question

[tierpolizistin]

So this question might not be exactly about Neuschwanstein itself, but I have always been rather curious, but can never find anything out about it. Since I was a little girl, I have been enamoured with Schloß Neuschwanstein, in Schwangau, Bayern, as well as it's creator, King Ludwig II. Now I do know that the castle was built upon an old ruin of a former castle, which was, I believe called "Schloß Schwangau", and growing up, Ludwig II was enthralled with the ruin and the location.

My question is this: does anyone know anything about that former castle, upon which Neuschwanstein was built? I mean, history, when it was built, who ruled there, what happened, why it went into ruin, etc? I have always been curious about it.

Thank you! :)