Charstar you have a computer, so try using Google.
When I needed to find out anything for homework or a school project I had to walk down to the library and look it up.
Just enter 'tribunal ' into Google and look through the answers for information.
Just to save you from typing a few words here is the 1st entry if you Google 'Triunal'
http://en.wikipedia.org/wiki/Tribunal
Read it and then do your own homework.
You are closer than you think Sandy 'tribunal' is derived from the Roman Tribunes and originally meant 'the office of the Tribunes'
Charstar now you need to Google 'Tribunes' as well to get the context.