A general is a non-combat unit, which can be attached to either an army or a defence force in your city. A general provides bonuses to the city’s defences or his army, but only when he is part of this army or defence.
Each general has a set of skill slots.
A general’s skill determines which bonus he gives to his army or city. When your general levels up - most of the bonuses will increase as well.
Where to recruit a general?