War Chest: Siege

From BoardGameGeek:

Not all battles are fought on the open field. In many cases defenders hide behind the thick walls of mighty castles. Now is the time to prepare for Siege! As castles grew larger and stronger throughout the middle ages, new ways evolved to scale, knock down, and even undermine their walls. In War Chest: Siege, you will be confronted with fortified locations. Fear not, you have siege towers and trebuchets at your disposal and hardy sappers to both build your own fortifications and undermine your opponents'. Can you successfully return to the battlefield with your war engines in this ingenious and engaging game of tactics and strategy? -description from the publisher