Following ingame lore:
As the previous Battanian king favoured peace/ collaboration with the Empire, Caladog's ascension to king resulted in Battania going to war against the Empire and as the leader of these mountain barbarians he is in part guilty of the crime of defeating the Empire. After defeating him in battle there should be the option of publicly parading and executing him in the capital of one of the three Imperial factions thus adding credibility to this faction's capability of restoring the Empire. In the eyes of imperials this should make a war hero out of the lord/ hero to defeat him and other unforgivable enemies of the Empire.
As the previous Battanian king favoured peace/ collaboration with the Empire, Caladog's ascension to king resulted in Battania going to war against the Empire and as the leader of these mountain barbarians he is in part guilty of the crime of defeating the Empire. After defeating him in battle there should be the option of publicly parading and executing him in the capital of one of the three Imperial factions thus adding credibility to this faction's capability of restoring the Empire. In the eyes of imperials this should make a war hero out of the lord/ hero to defeat him and other unforgivable enemies of the Empire.