There was a good reason that a knight spent years practicing his fighting skills. It prepared him to defend the lord and lady he served.
It also helped him to defend the castle that was his home. Sometimes this meant charging onto a battlefield. Just as often, the knight’s job was to keep enemies from breaking down the castle walls, getting across the moat, and forcing their way into the castle.
When enemies attacked a castle, they always first tried to take it by force. If this failed, they had a second plan called a siege. During a siege, the attackers surrounded the castle. They kept anyone from leaving or from coming in. Then they waited, hoping those inside would soon run out of food and other supplies and give up.