Honestly, its so annoying when the combat popup yells "YOU ARE UNDER ATTACK!!", and shows you a few peasants of yours being attacked.
Without ANY indication what so ever of where it is, if its an actually city attack, or just some peasants in a field, or some peasants auto-exploring.

What is vitally needed is to show WHERE the attack is taking place, either shrink the oversized combat popup screen and zoom the view to the location, or write the city name or "In the vicinity of CITYNAME" in the top row. It is almost to the point of being unplayable when you have no idea where attacks are taking place until after the entire battle is over.

As a related suggestion, there also needs to be some visual or audio warning when an enemy empire (you are at war with) enters your influence borders, or nears one of your cities.. It is so incredibly easy to miss an entire army strolling through the desolate northern parts of your empire.
You'd think the villagers in the city they just passed (with a watchtower even) would scream at the garrison to wake up rather than just let the huge enemy army stroll by while you, the sovereign, can take a nice nap.