have 1988 rolls royce silver spur that will not start and the back wheels will not roll what could be the cause

Seven weeks is not that long for a car to sit, but it is long enough for a battery to go dead. So get a fully charged battery in there. If rear wheels are locked up check the emergency brakes aren't set, after that it might just need some brake cleaner sprayed in the wheels. Rolls Royces are like any other car in the regard that they need maintenance too, this one sounds like it's overdue for some.