Firstly (and most importantly) this is NOT Gladiator. Different story, different country, different time. If you don't get this then stop reading as you are wasting your time.
Ridley Scott is THE Master of this kind of storytelling so enjoy all his films for what they are, not what you wish them to be.
Russell Crowe (accent faux pas' aside) is simply wonderful in this sort of role and Cate Blanchett is at her best since "Elizabeth I & II"). Mark Strong is excellent as the baddy and a vintage Max Von Sydow turns in a delicate performance as a man having to deal with the world changing around him whilst he cannot see it for himself.
Lots of strong performances from many of the supporting cast adds to the premise of the story that is, in effect, 'The Making of Robin Hood'.
More films should be made of this quality instead of the teen garbage that Hollywood spews out by the bucketload. Occassionally they get it right - as in this case - so we viewing mortals have to respect them for that and avoid the other dross so that it fails to make any money and they get the message.
Long live King Ridley and long live Robin Hood!