What does the very hard difficulty setting actually do?

[khelvan]

On the campaign map, the difficulty setting determines, more than anything else, how aggressive the AI factions are, including the rebels. For instance, only on "very hard" settings will you see the slave faction sieging cities.

[the_handsome_viking]

On the campaign map, the difficulty setting determines, more than anything else, how aggressive the AI factions are, including the rebels. For instance, only on "very hard" settings will you see the slave faction sieging cities.

But surly it effects the real battles?

[Telys]

On the campaign map, the difficulty setting determines, more than anything else, how aggressive the AI factions are, including the rebels. For instance, only on "very hard" settings will you see the slave faction sieging cities.

When i played on hard(setting right before very hard) rebels were besieging my cities.