
Basically the previous generation were not showing their fangs and trying to keep a balanced and cordial relationship on the surface. But the late emperor had ulterior motives and wanted to find out more about the Duke's land and his family secret aka the fangs power.The late Duke also seems to have known that the emperor was up to smth but didn't show it. This was also passed down to the current emperor (then crown prince) as we can see with his actions in the present and his hostile attitude towards Phileo.
What Phileo wanted to know was if their plan started from his generation or the previous...The plan being them trying to infiltrate inside the North to know the secrets of the Duke's family which is where they also tried to use Regina (Leo's morher) for it...The red head knight she fell for was actually a high ranked noble who worked for the royal family/emperor as we know now.
is it just me who didn't understand the thing abt the late emperor?