If you are going to attack the enemy's kingdom don't take your troops and attack,first group
your troops with some villagers and stay some distance from your enemy.Built fort(recruit 
trebuchets, if you are Britions recruit longbowman),stable(recruit Paladin),siege workshop
(recruit heavy scorpion) and attack your enemy with your troops.It will be more powerful and
you have non-stop supplying of your troops.