So he made his own children address him by his title?
In work-related situations people address each other by their title.
In some instances you may also address a Duke by his title.
I will remember to address your father by his full title in future.
Please address me by my correct military title, if you please.
Pontiff, I would appreciate your addressing me by my title.
"You must address me by my proper title," the man said.
As the older of my associates he had the right to address me by my short title.
"Forgive my sudden formality, but this is official business, and I really should address you by your title."
He hadn't realized that he'd ever addressed the captain by his title anywhere that she could hear.