When in the diplomacy screen the relations say that one of the leaders has a -15 relations and that it is because of "envy of the leader". What does that mean?
That means that you are considered the most powerful great mage, and that other mages envy you, thus have lowered diplomatic relations with you.
That means that you are considered the most powerful great mage, and that other mages envy you, thus have lowered diplomatic relations with you.