AHA! He did. He got nervous with me nearby so he marched out half of his units to try and find me.
I quickly did a Contact Deep Ones ritual calling for aid in my battle. I was answered by a Shambler Prince leading five experienced War Shamblers. I took a chance and gave him all of my troops to do the raid instantly. I did not want the searching units to return.
http://www.dom3minions.com/~gandalf/CoE3/AAR2/citadel_fight.JPG
He won the day! It was expensive. He only has 3 of his War Shamblers left, and none of my troops.
I could recruit there. A catapult would be nice. Or some archers. But I am low on gold. I might want to wait and see what will be thrown against me. I expect the Demonologist to come charging home. But if he brings a large army then I and the Prince can just step into the ocean. Or even that lake next door to it if it isnt winter. Let him take back his Citadel. When he marches out I will take it back again. We can ping-pong ownership forever. It will tie him up, waste his gold, and give my ally time to whittle away at our enemies lands.