Place the stockpile near the iron, place the granary in a safe spot, then immediately pause. Decrease the game speed to 10. You will want to finish the pre-built wall by extending it to the edges of the plateau you start on. You will not receive a notification that the keep is enclosed, but it will be if you do it right. Position your swordsmen and lord behind the gate and your archers in the tower.
Place 2 iron mines and 3 ox tethers. Set your estate to stone production. Buy enough wood to place 4 apple orchards and 4 chicken farms. Then place your (free) woodcutter, and spend the rest of your starting money to buy wood. Place two more woodcutters. Don't put them too close to the stockpile.
You should now place 5 hovels. If you need more gold, first thicken your wall to 3 layers where possible and build your armory near the stockpile, then sell the rest of the stone. Set rations to Extra and taxes to Normal. Make sure to place a few wells around the place.
You can now knock your game speed up to a comfortable level. If the enemy starts attacking, it would be wise to buy weapons when short on them. Don't be afraid to sortie out and destroy their siege camps. It is wise to focus on knights because of the abundant armor, so build armories and blacksmiths when you can. Crossbowmen should be your next focus. Buy leather armor, and have your fletchers make crossbows. If you feel bold to increase your population, you can make your own leather, but be sure to place a couple apple orchards or chicken farms for new houses.
High honor is critical in order to field an army of knights. Be sure to build a pantry and som food buildings when you have soem spare wood.
The enemy will be fighting uphill, but this hill (despite its massive height) has a gentle slope. Do not expect miracles when charging down it. The first few enemy assaults may be costly for you. Keep the walls manned and defend the staircase on the barracks, the tower and the gatehouse especially with swordsmen and your lord. The fiery imps will be your worst nightmare if they get past your walls. Spread out your swordsmen a bit and make sure to put them on defensive stance.
Your strategy should instead focus on defensive lines. Once you have a number of troops, put them on the border between your estate and the neutral estate. Put your crossbowmen behind (but not too far behind) your knights. Keep some men at home in case any enemies get past your first line.
When you gather a substantial army, capture the estate that started as neutral. Set production to iron. If you are still running out of iron, increase production at home. While you are building up troops on the edge of your second estate and Vlad's castle, be sure to place trebuchet on the edge of your home cliff. Protect these with crossbowmen in case of bat or dragon attacks.
When Vlad's castle starts looking like an abandoned shack and he isn't training too many troops, attack! I sent in 33 knights and Arthur and it was a piece of cake. Defend the gap between this estate and Vlad's castle. Again, you should have a large force by now if you are to survive with such a long supply line. Don't get too close!