This trophy is called "
The Beginning" and it is an unmissable story based trophy for completing the opening mission, "A Journey's Beginning."
*** Spoiler - click to reveal ***The mission is fairly straight forward. Use the hero to attack the enemy units on the map. After one or two turns, an ally will appear on the map to help the hero. After a couple more turns, enemy reinforcements will appear on the map, but the battleship Dreisstrager will launch and defeat them. After defeating the remaining enemies on the map from the start of the mission, two more enemies will appear nearby. Once they're defeated, the mission will be completed. The trophy will unlock afterwards between scenes.