The Lost Prince Solution

Part 1: The Village

At the alehouse, gamble until you have won 2 coins. Also talk to the barkeeper, asking about the name of the country.
At the blacksmith's, ask about the knight and take all of the reject weapons.
Visit the cave.
Go to the bookshop, buy a bible, ask what the man is reading and buy the handbook. Examine the handbook.
Talk to the thief, asking about the sword, then chapter 7.
Go to the beach and take the rope. Use the axehead on the rope.
Go to the castle and use the axehead/rope on the moat.
Give the sword to the blacksmith. He will now let you take the cutters.
Go to the wood and use the dagger on the tree. Blow the horn. In the outlaws camp, choose the archery test and use your own arrow. Return to the camp and exit at the other side. Talk to the bard, offer the bible in exchange for the harp.
At the cave, play the harp then use the cutters on the princess.
Return to the camp and blow the horn.

Part 2: The Castle

Use the axehead/rope to get the key from the dragon.
Go to the kitchen and take everything possible.
In the Black Knight's bedroom, use the chest and take the club.
Use the stool on the ivy outside, then examine the book. Note the three dates.
Go to the treasury and use the large box. The three dates are the combination. Before the guard arrives, use the smaller box twice.
Use the bricks to escape. In the passage, use the club on the bricks.
Use the cheese on the hole, then use the dagger on the bow. Use the string on the rat and the string/rat on the bowl. Use the stick to get the keys and use them on the gate.
You can now enter the study. Take the magic book and all of the bottles.
Go to the Black Knight's room and use the book on the mirror.
Use the axehead/rope on the bucket. Use the bucket on the well. Use the well handle twice.
Use the wood on the fire. Use the pot on the wood. Use the pepper on the dragon. Use the bucket on the pot. Prepare the recipe in the magic book.
Take the pot.
Go to the study and use the powder on the carpet.

Part 3: The Forest

Take the key and the lantern. Use the key on the lantern to find the route to take. Repeat this until you come to a building.
Use the red bottle on the plant.

Part 4: Underground

Explore the maze until you find a hammer (take it), two signposts (use the hammer on the nails), and a lift (Use the nails on the floor).
Use the rope.

Part 5: The Witch of the East.

Use the cabinet, take the wine bottle, use the wine bottle on the cauldron, use the wine bottle on the cabinet, then use the cupboard twice.