It's going to be the Early Modern Period, from the late 15th Century to the late 17th Century. So primarily the Age of Discovery and the Wars of Religion.
They have already confirmed that the new historical game will not be a sequel; it will not cover a previous time period.
We can also be certain that the geographic focus will be Europe as TW games cater to a mostly Anglo-American or Western audience. Japan is pretty much the only non-Western locale that many in the West have any interest in (in terms of pre-modern battles). And we've already done the entirety of Japanese military history that anyone would have interest in.
If we look at the European military history timeline we realize that every single period from Classical Greece (4th Century BC) to the Napoleonic Wars has already been covered...
EXCEPT the 15th to 17th Centuries. This period is the gap between Medieval TW and Empire TW, AKA the period of "Pike and Shot".
An earlier period game (so prior to 4th Century BC) is highly unlikely as it would no longer be focused in Europe. While I'm sure some people might find "Bronze Age Total War" to be interesting, I don't think the idea would pass muster with business executives; it's just not something many players are familiar with or interested in.
A later period game set in the Victorian Era is also unlikely for 2 reasons:
- The "Long 19th Century" from the end of the Napoleonic Wars to the start of WWI is a relatively uneventful period in European military history. Yes there was the Crimean War and the Wars of German unification, but these were short localized wars, not the fodder for a base TW game, an expansion pack perhaps, but not a core game setting. TW games are always set in a period of high intensity warfare between belligerents of roughly equal power, the classic "warring states" model, which doesn't apply to the 19th Century. You can argue "alternate history", or "WWI in 1870", but I honestly don't think that will fly for players who like to re-enact major historical events.
- Victorian Era warfare is just not too diverse tactically speaking as we learned from Shogun II FotS which covers the same period but in Japan. FotS was mainly entertaining as there was the element of abrupt modernization so you had sword wielding samurai fighting Gatling guns. The same scenario does not apply to European warfare of the period unless we include colonial warfare. And I don't think they will make a game focused on colonial warfare. Conventional war between European armies would be too focused on firearms as cold steel was rendered largely obsolete by the 1860s as evidenced by the American Civil War. I can't imagine that CA will release a TW game where melee combat isn't a major focus.
So purely by the process of elimination we can see that a pike and shot period game is the only viable option. And it's a fantastic option:
- Perfect "warring states" political setting with almost continuous Europe-wide warfare between the major powers.
- The religious conflict between the Protestants, Catholics, and Muslims is classic TW game mechanic fodder. So many potential mechanisms for religious struggle come to mind.
- Tactics are more diverse than in any previous or succeeding period. The Pike and Shot period, as the name implies, is the transitional period between medieval cold steel and modern firearms. It is a time when the pike and sword were just as important as the musket and cannon. The technological race is also a major element that can spice up game mechanics as nations research better firearms technology.
The last stand of the Spanish infantry at Rocroi, 1643.
Rocroi was a decisive defeat for the Hapsburgs towards the end of the Thirty Years' War, a war that could easily be a TW game all by itself.