Live through the ages, conquer kingdoms and build up your empire. Empire Earth by Sierra is one way to do just that. It spans through the dark ages in Greece to the ultra modern world with the Russians. The campaigns depict popular events in civilizations like Greek, English, German and Russian. The game is highly immersible and gives complete control of your empire to its king(yes, its you !!). Every campaign has specialized units belonging to a particular civilization giving you insight about them.
Pros : Great campaign based on actual historic events, units are well defined and have great variety and gameplay control is good.
Cons : Behaviour of some units is strange