The timeline even stretches from just after the Battle of Hastings in 1066 all the way to the early 16th century, which allows for a great evolution in battle hardware and tactics. You start fighting over the usual European battlefields with ancient hardware like swords and end up possibly using cannons to battle Aztecs in the New World.
There are a few drawbacks to this Middle Ages madness, however. Enemy troops seem more resolute than before, so they aren't as prone to fleeing in panic so readily as in past Total War games. This is generally a good thing, but it sometimes results in battles dragging on as foes quickly rebound, no matter how badly they're being beaten. You can get into long battles of attrition and wind up in draws even after demolishing an enemy's castle and killing all but three or four of his never-say-die crossbowmen.
All the campaign improvements mean that other modes of play have taken a back seat again. Despite the demand for multiplayer additions like online campaigns, you can still only take part in one-on-one battles with other human monarchs. Solo battles against the computer are also limited, although at least you can custom-design engagements and replay seven historical battles, a line-up that includes titanic clashes like the Battle of Arsuf between Richard I and Saladin and the spectacular siege of Setenil during the Spanish Reconquista.