In the first campaign of The Winds of War, we get to guide a young king Spazz Maticus through his quest to expand his domain a little. The first target of his conquest is a region of Anduran Foothills, which will give him the necessary resources to continue further to his ultimate task of capturing Channon.
Spazz starts his quest as a Level 5 Witch King, with advanced Chaos Magic, and basic Conjuration, Pyromancy, Nobility and Estates. That's quite an interesting setup, as a Witch King is one of those classes with cool bonus that you rarely get to actually play - he is imbued with the ability to strike Fear in the hearts of his opponents, much like a Bone Dragon. Unfortunately, the primary skills (Chaos and Nobility) make him VERY vulnerable in combat, and it's likely he will change the class very soon. Which he did, in my game - as I play on Champion difficulty, I find that high Combat and Melee are an absolute must for survival.
Spazz doesn't start with any towns, but he has a rather large army of Bandits, Orcs and Minotaurs at his disposal, and he knows some basic spells, including direct damage. With these resources he shouldn't have any trouble beating the nearby moderately-sized neutral armies, and still have plenty of loose bandits to send as scouts. Too bad all the mines around are undeveloped, and require an investment of Gold and other resources - something you can't afford for now - to start working. Fortunately, these mines can be flagged by creatures alone - just leave a single bandit around to claim them when you earn the necessary amount of Gold.
I recommend to head eastwards, liberating a soon-to-be Woodmill on the way. About a day's walk away there's a lightly guarded area with a Learning Stone, a Treasure Chest, two Crystals (Speed and Magic) and Surefooted Boots, all of which are very useful to get ASAP. Then you can start capturing towns. There are three Asylums in the accessible area: One is right in the center of the map, another lies in the south-east corner, and the third can be found in the center-east. All of them are guarded by the standard guards - about 50 of both Orcs and Bandits, and about 15 of either Minotaurs or Medusae. The order in which to capture them doesn't really matter; I went for the central town first, then east and finally south, but the east-north-center direction is just as viable, if not even better, as you will be doing most of your further attacks from the central town. In all of the Asylums you can build creature generators up to Level 3, and all miscellaneous structures. Just don't forget to build and visit all three Thieves' Gauntlets and Battle Academies!
When you secure all three cities, you will have just three more tasks to complete:
1) Clear your conquered area of neutral creatures, gathering artifacts, mines and resources, 2) attack the northern "bonus" area, 3) and finally invade the north-eastern area and crush Erutan's forces.
For now, you can focus on point 1. You will be safe from Erutan for quite a some time, as the lightly guarded entrance to his domain is overgrown with trees, and the other pass is heavily guarded with Level 4 units neither you nor he will be able to beat for quite a some time. The bonus area is also heavily guarded by Unicorns; I found it easiest to leave it alone until you capture some of Erutan's Preserves, as the Water Elementals from their Portals can take care of the Unicorns quite easily. The access to Erutan will open automatically late in the 5th week or early in the 6th.
Erutan's forces shouldn't present any serious problem, as they only have one town for quite a long time, and only one stronger hero - about level 10-12. He will probably manage to capture the two other preserves by the time you reach him, but they will be underdeveloped and only lightly guarded. You can easily conquer two Preserves, capturing the heroes in the process. A small army of medusae placed in front of the remaining town's gates will confine Erutan to his lair forever, giving you time to attack the bonus area.
Which you should do once you are safe. The guards will supply you with the much-needed experience points, not to mention the numerous crystals, a library, and other bonuses. Water Elementals with their Quicksand, Fatigue and Ice Bolt will let you kill the Unicorns quickly and without any losses on your side. In the farthest corner of the bonus are you will find Armor of Life, Mayhem Staff and Sandwalker's Sandals, which will accompany you to the next map - a worthy bonus indeed.
When you are done with your work, return to Erutan and finish him off. By that time my Spazz reached level 15, which is the maximum level in this scenario, and became a Fireguard with master Combat and master Chaos magic.