Examples from literature

• Ducal authority was accomplished almost of itself. 
• During his reign and the reigns of his successors, Francis I., Peter II. and Arthur III., the ducal authority developed in a remarkable manner. 
• Even so—and that upon the morning of the ducal election, the third of this month. 
• I swear it by my ducal crown, and by the order that I wear. 
• The ducal palace, and the monastic buildings of the priory, once connected with it, are now completely destroyed.