If not, then select the Games drop down menu and select. If you bought it in Steam, then select it from the list on the Library tab and click the Install button. › How-do-you-install-Third-Age-Total-War-through-Steam. It will automatically create a Third Age folder in your mods.
\Steam\SteamApps\common\Medieval II Total War, asuming you have the steam version. Includes 2 items: Medieval II: Total War™ Kingdoms, Total War: MEDIEVAL II – Definitive Edition Requires agreement to a 3rd-party EULA. Seeing as everybody's so utterly clueless about installing Third Age: Total War, I thought I'd tell you how to at least install it.