Judge’s chambers

I don’t understand why a judge’s office is called chambers.
Everybody else’s office is called an office.
Why not call it the judge’s office?
And besides, the judge only has one office, so why not call it a chamber?
It sounds like some Dungeons and Dragons kind of thing, a chamber. A creepy chamber.
Like the judge is a monster, and the adventuring party is sneaking in to kill it and steal its gold.
Maybe that’s what they do in the chambers… they fight to try to steal the judge’s gold.
No wonder why they bring their briefcases with them.