Seize is a map objective used throughout the Fire Emblem series.
Overview
The Seize objective requires that the player capture a castle or a throne on the map to complete it. This is accomplished by positioning a unit capable of seizing the target in question and using the 'Seize' command. Doing so immediately concludes the battle as a victory for the player.
Typically, Seize maps have a stationary Boss defending the target who must be defeated before the position can be seized. The functional act of seizing a position is typically given to the Lord character, but depending on the battle in question, other units may be allowed the action.