This is the first part of mission 5 in the Path of War in Stronghold 2.
You (as Steele) are commanded to dispatch a greedy Olaf, who attacked and robbed Friar Jacob's monastery. Olaf has established a small fort with multiple defense lines, which you must raze, forcing the Viking leader to retreat and release Sir William from captivity.
You get numerous spearmen and warrior monks, some archers, the Lord and 4 catapults at your disposal. In front of the first walls, 4 fire ballistae with a few berserkers are located. They start firing at your troops, so divide your army into six or seven small groups and in column formation, send them to the ballistae to destroy them. Meanwhile, leave your archers and catapults behind and when your troops are halfway to the targets, send your lord to join them. You may suffer some casualties, but the hardest part is yet to come.
While the ballistae are being destroyed, Olaf starts to send out large groups of berserkers to catch your Lord. Some of them moves faster, but most of them just walks steadily. Don't waste your spearmen and monks on these troops, bring up your archers and catapults instead. Move back and forth with the Lord to distract the incoming beserkers, and use archers to finish them off.. You can also make extensive use of your catapults, as they can send units fly, packing a high punch. Three berserker waves will come to suicide.
When everything is clear, now it's your turn. Bring your archers near the wall and annihilate the axe throwers on it. Stay out of the defenders' range, they are devastating in close combat. Right after the first wall, there are two more fire ballistae behind them. Use the catapults to destroy them, ensuring that you don't destroy the walls or they can fire on you.
Proceed to the next wall and repeat the process. When you're near the final wall line, Olaf will command his troops to retreat, which means you have won.
Olaf, in a last ditch attempt to kill Sir William, knocks a bucket causing William to choke to his death before fleeing. Fortunately, Steele hid himself in a nearby bush and grabs an axe embedded in a nearby tree, throwing it at the rope. The axe hits the rope, freeing Sir William and he thanks Steele for saving his life. Friar Jacob and Sir Grey appear, with Jacob happy that Olaf and his men left most of the looted treasures behind. But Sir Grey tells Steele that he has gotten reports of Edwin's army headed their way, to his disgust.