The Roman Senate was a "what" of wealthy powerful Romans that advised the Cities leaders?

Question

The Roman Senate was a "what" of wealthy powerful Romans that advised the Cities leaders?

Answer 1

The Roman Senate was a 'political institution' of wealthy, powerful Romans that advised the Cities leaders

Answer 2

political aristocratic privileged body

Answer 3

That "what" could be filled with a number of words that mean the same thing.  Try something along the lines of political body...