Start with storming the mine to the northeast (1). Expand your territory due North, conquering the second city (2) and another mine. After a while you'll join forces with Distuzio, who will provide you with even more Timonium sources.
Expand your economy, using your troops to gain control over more and more neutral spots, including the third city (3). The enemy is unusually passive in this scenario, all he does is sending some suicide attacks on Distruzio and his men. There's a bonus quest to take control over all Condottieri outposts (4).
When you control the whole map save for the enemy territory, gather your troops and strike the opponent down.
You have to choose 3 heroes who will accompany you in this one. You don't have a base here, all you do is commanding a small strike force.
Destroy the enemy mine (1). Follow the path and free the Golem, which will trigger a bonus quest Find the Master. We'll get to that. Break into the prison and free 4 lieutenants that are being kept here (marked with *). Any troops you free in here will join you, so take your time. Freeing the Genie (3) will complete the aforementioned sub-quest.
Your last task is to free the last lieutenant, the one who is being held in a special cell (4) and guarded personally by the Warden. You have to kill the latter. Hurry up, as you have a tight time limit for this one.