Commanders are used to send soldiers from one castle, outpost [etc.] to another. They are used for supporting, and attacking. In similarity to castellans, each commander can be assigned special bonuses with equipment. Before sending your troops to a battle or supporting another castle [etc.] you must chose which commander to use, depending on the bonuses each commander gives. You may wish to rename commanders based on specific bonuses. There are a maximum of 21 commanders you can use, if your Encampment is at level 7.