A century, and yes. How much land, though? And what is it worth? Who lives there? Will the land be arbitrarily divided along the interests of the dragons, even if it means tearing communities apart or shoving dissimilar groups together?
alright keep in mind I don't know the entire scales of villages to kingdoms when I say this. I only plan to control the elven lands I would happily control a small kingdom to protect its citizens and if need be I will handle dealing with different groups interacting with one another.
You can have your dragon heading to see his dying relative. Like, you can have him flying through the air and approaching the mountain palace. Note than it is a mountain with golden palace building into the mountain, with palace parts sticking out of the mountain in places. Not a giant golden place on top of the mountain.