Crusade is the eight map in the Ascent of Egypt Learning Campaign. The mission shows you how to convert enemy units.
The great new temple has had a powerful effect on the people of Egypt. Priests are revitalized in their fervor and are spreading the word up river and along the coast. You are leading a new settlement in the west near Libya where raiders have been harassing Egyptian towns. These raiders possess a powerful new weapon called a Ballista. Capture the Ballista and bring it to your Town Center.
Capture (convert) the Ballista and bring it to your Town Center.
This map can be won in a matter of minutes. The ballista you're after is just south of your town, and you start off with a priest. Train a scout, and send the two units down to the ballista. Send the scout in first, to dodge ballista shots while the priest converts (but make sure that the scout doesn't move too close to the priest, or the ballista might hit him).
Once the ballista is yours, finish the mission.