And then there's FE11 which takes place across the two continents from the first three games nevermind all the other references to the rest of the series (some of which are massive spoilers for FE11 so I'm going to avoid going into details at this point). Plus, the DLC for the game lets you recruit various main lords from the prior games, so to head off the classic question of "Is Marth and Roy in this?" the answer is yes. (Also it too involves pairing up characters for their offspring like in FE4.)
FE11 is Shadow Dragon. FE12 never came out of Japan. You're thinking of FE13, Awakening.