A holy order is an organisation of religious warriors which can be hired by a ruler of corresponding religion to fight for them. Holy orders cost piety to hire and require a monthly upkeep of a few gold. However, in a religious defensive war they have no monthly upkeep. The leader of a holy order bears a title of ducal rank, representing that order. Holy orders can be landed or unlanded, but are unplayable either way. If a holy order is in fief to a king or emperor, only that holy order's liege can hire it.