This is mission 4 in the Stronghold Crusader skirmish trail.
Enemies: 1 Pig (orange)
Game mode: normal, slight AI advantage (4000 gold)
This is the first mission in the trail, where the enemy has an advantage. However, it is very easy to pin down your adversary. Site the base buildings and start gathering wood, but spare some for a quarry and oxen for the deposit in the south. Start producing bread. You may need many wheat farms for surplus gold. Build the engineer's guild.
Defend your territory with a square tower and have 10 crossbowmen and some Arab archers on it along with a mangonel. Target the mangonel as close to the Pig's castle as possible and start hurling stones. Spend all incoming money on assassins. When you have 7-8 of them, destroy all enemy buildings surrounding your land, but don't infiltrate the castle. Set these troops on 'aggressive'.
When you have the option, place more Arab bowmen and portable shields in the tower, as the Pig will send crossbowmen to counter your action. Some macemen may also attempt to break into your tower. Fight them with your Lord, but withdraw once they are all annihilated. As the Pig has gone bankrupt, start making additional assassins.
When you have 30 (or 40) of them, lead an assault on the enemy Lord. You may have a clear path into the keep, ignore the defenders. You may lose some troops to killing pits and friendly stones, but an easy victory awaits you to achieve.