Armed Citizens (or Farmers) are defense units which cannot attack or be recruited. They automatically appear in a castle with a civilian population. They have weak defense, but it's better than nothing. To get more of these the player must build or upgrade either dwellings or townhouses. 20% of your population will be these, e.g. 100 pop. = 20 Farmer/Armed Citizen. With the research tower, you can research milita. They replace your armed citizens with a much stronger version (although still weak compared to other soldiers). They are somehow revived after each battle.